I have made some progress with a Tower power supply replacement. The 44 pin connector is not proprietary and is a modern sourceable part and it's still manufactured. The design will be open sourced once it works and I have a reseller willing to sell them once working so people can get them. The end state is a beginner level soldering installable replacement for these computers. We know those tower PSUs are a pain even after a recap they seem to die. This has happened to me twice.
At this time my board simply functions as an ATX adaptor where you need the second switch in the back for it to function. However I'm exploring circuits at this time to turn the PSU on with the original power button and an operating system shutdown function through townsOS. This would place this PSU as a direct 1:1 replacement in terms of functionality.
A shorter version without the 12V DC converter is also possible if you can fit an ATX inside the original metal shielding. For the 220V countries this means you won't require a step down converter.
Attached is photo of my current board. The circuit onboard doesn't work. I have the proper pin out for the 44 pin backplane connector and the computer does turn on if you force the power on. However the original power button isn't working to turn it on. I attempted a latching circuit and unfortunately it isn't enough. I'll be attempting a new circuit later this week.
For those with electrical engineering experience I would love some input with this. If this project is completed a solution can be made for the desktops as well with the same circuit if it works for towers. Towns seems to use two different power supplies all together.
Great Project.
I managed to use the powerbutton and softpower via an ATX Adapter designed by Ian Steadman for Amiga Computer.
The lower 2 pins from the 44 pin connector are for that. One ist power button the other softpower. I mean they switch to GND. I use the Ian Steadman adapter with momentary so the power switch works.
Can you use this circuit on your PCB ?
Very interesting, good job!
Quote from: Jehuty on January 06, 2021, 05:56:07 PMGreat Project.
I managed to use the powerbutton and softpower via an ATX Adapter designed by Ian Steadman for Amiga Computer.
The lower 2 pins from the 44 pin connector are for that. One ist power button the other softpower. I mean they switch to GND. I use the Ian Steadman adapter with momentary so the power switch works.
Can you use this circuit on your PCB ?
I tried it a while back but haven't revisited. I think I was programming MCU incorrectly. I should get parts this week to try a different circuit. If it doesn't work I will revisit that one
looking good so far, and very cool that you are doing something like this!
Leyline power supply board seems to work as untended so far... Well it passes LED test. So I will try to add it into a dead HR100 that arrives at my house soon. If it works the circuit can be exported for use for the tower models also. This PSU card works for all Desktops to include HG, HR, MA, MX, ME and Fresh models. It won't work with HA family of parts Pentium series and won't work with FMV as I don't own these PC to test them.
It takes some inspiration from mattsoft's project for X68 where it uses ACDC converter and pico. I made an on board circuit so you can keep use of original power button. I also added connector for noctua fan and stock fan. Has 5Vstandby LED and power-good LED indicating it turns on when the on-off line hits ground... Or when you push power button on front of the PC. I believe it should work but I'll test in a few days/weeks on my dead HR100. This will also work for 220V countries as the ACDC converter I used is 220V compliant as well.
Following the BEEP Magazine scans of the power wire pin outside, you cut the wires from your Dead PSU and use block terminal which is clearly labeled. I would personally recommend just soldering the wires without block terminal but I will test both before releasing this. I find this better than the ATX wiring methods.
It's very expensive to assemble and I won't be selling this as I only made it for a few friends of mine. However it will be open source and I will include assembly instructions that must be VERY carefully followed and bill of material. The only stock functionality that isn't implemented is operating system shutdown funtion when you select power off in townsOS and you will lose functionality of the power receptable in the back. However for most users it shouldnt be an issue.
I think more people want to see tower PSU card more :)
Friends,
I have finally made a PSU that keeps the integrity of the original power button. I added noctua connector to tower and desktop PSUs. I tested the script with my Arduino on my HG/HR and plan to replace all my Towns PC with this PSU I designed. I personally cannot stand that 12V standby that wrecks these 30 year old ICs and diodes hanging by a thread. Fits almost all desktop except I can't verify FMV Towns.
I'm sending to fabrication for final testing before releasing this into the wild for everyone to use and it will be on my github. For the Desktop PSU you need to cut the wires from your dead power supply and then solder them to the new card. Follow the BEEP manual scans I posted a few months ago and you will be fine.
I also added connection for "TownsOS power off" function if someone wants to program Arduino later on to add that feature. My script doesn't have it implemented because I can't be asked.... I believe 99.999% of people don't really care though :p
Also this is 220V and 120V compliant because I use the Meanwell EPS-120-12.
Oh quick update.
The script is updated and it can now turn off via TownsOS. So this is true 1:1 replacement. I would highly advise at this point to consider throw your 30 year old PSU in trash.
Give me a week or two to final test new boards when they arrive.
Great news. Waiting for 1 - 2 PCB.
Just joined this forum for this great initiative.
I have an FM Towns 2F sitting on my desk that had a dead PSU, although I had changed all the capacitors, before the PSU died some hours of use later.
Jehuty has supported me in connecting an external ATX PSU to the original PSU board, but this is far from original and requires a lot of space on the desk - plus complete immobility of the entire system.
I am hoping to get one of your new PCBs.
Good luck.
The Tower PSU card 100% works turning on and off. I'm sending it to my tester for final stress testing.
https://www.facebook.com/groups/298509760178487/permalink/4354469217915834/
Provided it works fine as it should I will have 3 left for sale without ACDC converter and pico PSU. $40 before shipping. After that the tower PSU bill of material and board files will go to GitHub for everyone to use. I will also try to get an eBay seller to have some in stock eventually
Arduino controls the power supply on and off button as it runs on 5V standby from the pico PSU. It also can perform TownsOS power off function when you select it in TownsOS.
And again like all things one more revision is needed. Well I want to get screw holes perfect. Here is few photo of tower PSU test unit. I ordered 50 PCB with slight adjustment and I will hand assemble. The final material cost to include pico and ACDC converter is $95 USD and only that low because I buy in bulk. This was very long on and off project of mine but it's finally coming to a close. It uses high quality components no fake pico to destroy Ricoh sound chip :)
If anyone wants to buy it's $140 shipped in USA. I'm not sure price to ship to friends in Europe but I will take a look later.
Hopefully people can appreciate the time, testing, R&D it took for me to make this. I will have installation guide later for it also. Only 4 wires are required for soldering. The only difference between this card and stock card is that it is 86-286VAC compliant (yes for you 220V country you don't need step down) and receptable in the back is based on your country power. So if you're in Europe don't connect FMT monitor to that receptable. You have been warned.
http://imgur.com/a/LZcSTpB
Here is some photo from test card.
It was tested running super street fighter 2 for 24 hours. Floppy drives work find also and hard drive loading also works fine from my tester and myself. Double goteks inside CX20 also work fine. Wizard ODE also work fine.
Desktop revision card is also coming from factory next week. It fits inside HG/HR and EA type desktop metal shields. It should also fit inside the desktop between those (4 expansion slot type). Won't work for Pentium towns or FMV. Unless someone want to sell me HC53M Pentium to study and make something. Everyone this is now your chance to let me know you want it because BEEP store.... I don't know what their markup is going to be.
Please check it.
https://townsworld.com/2021/05/08/fm-towns-tower-power-supply-assembly-guide/
I have a few fully assembled cards. Assembled, cleaned and tested ready to ship. It's 140 USD shipped in USA. Overseas I think is only $20 more and don't worry about VAT.
Still working on porting this concept to desktop card. So far desktop card plays FDD and sound totally fine. It won't load hard drive or CD ROM at all. So have to troubleshoot that.
My 20F has a PSU rated at 90W. But do you know the wattage load distribution of this 90W is on each of the three power outputs (5V, +12V,-12V) from the PSU?
Quote from: kamiboy on May 12, 2021, 12:03:22 AMMy 20F has a PSU rated at 90W. But do you know the wattage load distribution of this 90W is on each of the three power outputs (5V, +12V,-12V) from the PSU?
All towers are 90 watt.
You can check the manual for ITX PSU from the website. It's enough amps to drive everything.
I bought a model 2 (gen 1) tower to see if my card can work.
It can't.
However I'll design something that can fit inside the metal shield. Connector is totally different but it can be recycled into a new card.
Generation 1 card is done. Surprised I nailed it first time. Well a few holes don't line up 100% but that is trivial to correct.
Anyway it works in my MODEL2 perfectly which had a dead card inside it. Of course I have learned my CD Rom drive laser is trash and barely (mostly doesn't) read pressed CD.
http://imgur.com/a/bzflYZ4
Anyway I have 4 more of these PCB and they were expensive since they're very large. If you need any just message me.
Still working on desktop card
Installed one in my 2F. It works very well! I had to file down most of the holes since their positions were off (or in the case of the holes around the connector, too small). You should add back the power passthrough relay in future versions, the user can always just desolder the old one off their old board.
fmtowns2fpsu.jpg
There's actually enough space in the PSU shell to use a (de-cased) 1U/Shuttle/FLEX ATX PSU PCB. Sometimes those can be salvaged for much cheaper than new Pico PSUs can. Would be good to have alternate mounting holes for stuff like that.
Quote from: dankcomputing on June 21, 2021, 05:07:27 AMInstalled one in my 2F. It works very well! I had to file down most of the holes since their positions were off (or in the case of the holes around the connector, too small). You should add back the power passthrough relay in future versions, the user can always just desolder the old one off their old board.
There's actually enough space in the PSU shell to use a (de-cased) 1U/Shuttle/FLEX ATX PSU PCB. Sometimes those can be salvaged for much cheaper than new Pico PSUs can. Would be good to have alternate mounting holes for stuff like that.
Yh I thought of shoving ATX inside also. I guess it depends on what part of the world you're in and skill level as far as installing one of these.
It's so frustrating getting those holes right..
Oh and regarding using ATX.
The old mods everyone keeps grave digging on this forum involve using physical switch to force PS_ON to ground. Also involves lot of bulky PSU outside the pc. This is 2021. There is better things.
I have completed a desktop card that works in my HR100 very well but I question the upfront costs. It's almost $100 to assemble. So a better way is to use a smaller card. This blue card has the Arduino on it. Desolder dead PSU wires and solder them to the card. Then if you can, shove it inside the metal shield or tape it up and leave it inside computer (but outside metal PSU). Shove your mini ATX inside the original.
Here is photos of tester. For helping I give him free ATX and blue card.
http://imgur.com/a/QgxONkQ
The N/C line for desktops is to control fan speed and all desktop has this wire. I ignore fan speed and have it full blast. Anyway, this is the retail/public card I'll release once I have enough photos detailing how to install in all the desktops. I can tell people to read the BEEP manuals I got from Mr. Hota but I have a feeling they mess it up anyway. I need those photos before feeling comfortable letting it into the wild
For those that message me I'll message you tomorrow after I build your cards. I only have components for a few more. Not a lot.
I have remeasured PCB and made my changes to the Tower card. The generation 1 card I privately made for myself will be added this weekend when I measure PCB again. THAT card only works on the very first FMT Towers that need the SCSI card. I'm specifically trying to see if I can rearrange stuff on PCB to accomodate mini ATX before throwing it on github.
Here is files for the GEN 2, 3, 4 card.
https://github.com/cyo-the-vile/FMT-ATX-TOWER
I want to say thank you for your work. I got mine in the order with from AmigaDepot.
But my first try ends up in an dark room after i killed the room fuse. My stepdown converter touched the housing, the plastic bolts were a little bit too long. But now it works perfect.
Oen question, where did you get the connector to the motherboard ?
Quote from: Jehuty on July 02, 2021, 03:41:45 PMI want to say thank you for your work. I got mine in the order with from AmigaDepot.
But my first try ends up in an dark room after i killed the room fuse. My stepdown converter touched the housing, the plastic bolts were a little bit too long. But now it works perfect.
Oen question, where did you get the connector to the motherboard ?
It's a currently made part. I bought a lot from Mouser. I had 25 of them but now have 6 left. I think Mouser is out of stock. Arrow also has it for double the price.
You don't need a step down converter with this card
Oh sorry, doesn´t mean a stepdown converter from 230 to 110V, i meant the 12V PSU.
The pico can't touch the metal shielding. Well, the 160watt one can. My tester used a 160watt and it touched the top of the metal shielding during 24 hour stress test. I used the 120watt one in your card and it isn't touching the shielding or shouldnt be. Something else blew that fuse.
For sure it was the 12V PSU. I saw the impact on the metal shield. It was my fault as i didnt see it before i pluged it into 230V. But nothing gone defect so it was only a little shock, not more.
I still have 3 cards left. Still available for $130 shipped anywhere in the world.
Also don't do goods and services because then I have to pay a fee. Everyone keeps doing this to me after I explain the total and this include last 3 people that message me. If someone do that again I'm refunding you plain and simple.
I've revived 12 dead computers total to people I sold to in this forums and the group. Remaining 9 I sold were more or less modern PSU conversions. So stop fucking me over with paypal fees for goods and services.
---------------------------------------------------------------------------------------------
On a lighter note if you wanted to make your own cards and have questions feel free to message me. I have no issues pointing people in the right direction. The tower card I posted to github I tried to correct the holes that I messed up on as dankcomputing pointed out. Well I like to think I got it right finally. I also moved the ATX style connector over so people might give a shot bolting an ATX power supply inside if they wanted to. You should have enough room if you remove the metal casing of the ATX and bolt or glue the PCB on. The ATX or AC/DC & Pico combo I guess you can choose either one depending on what's cheapest for you on your side of the world.
I'm still working on the Gen1 tower card. I mean it functionally works but the fact that it cost $40 for 5 cards is annoying. It's the PCB size and not even the fact that I did a 4 layer board. I'll keep you guys posted when github is updated.
Github has been updated;
Added Gen 1 card support.
Desktop support will be slowly added in seperate repository in a week or two.
https://github.com/cyo-the-vile/FMT-ATX-TOWER/releases/tag/1.0
If you have no idea how to assemble the Gen 1 card please contact me before blowing up your towns. It isn't as plug and play as the other Tower models.
For anyone looking I did a small run of cards again for some friends. I have two left.
Hello everyone, I have won an FM Towns Fresh in Buyee, and I would like to update its PSU. the project of the new pcb continues?
Quote from: fidelware on October 26, 2021, 04:26:50 PMHello everyone, I have won an FM Towns Fresh in Buyee, and I would like to update its PSU. the project of the new pcb continues?
I wasn't able to find a pico that pushes enough power on the 5V line. Counterfeit pico worked but I can't honestly recommend.
What you can do is get a small flex atx and de-case it. Then go to GitHub page and load an Arduino pro micro with the firmware.
Cut the wires from dead power supply and basically match it to ATX. Trim the wires and match the correct voltage to the original stock wires. You need to use the BEEP maintenance manuals as a guide as it gives you the proper ones.
PS-on, OS-off, 5V standby, power on/off wires need to be soldered to pro micro. Then cover it in tape.
Be careful as I remember the 5V and 12V wires I think are both brown. You need to follow the scheme in the maintenance manuals that Hota-san scanned for me.
ok, i will try, thank you very much
Quote from: Cyothevile on October 27, 2021, 05:52:16 AMQuote from: fidelware on October 26, 2021, 04:26:50 PMHello everyone, I have won an FM Towns Fresh in Buyee, and I would like to update its PSU. the project of the new pcb continues?
I wasn't able to find a pico that pushes enough power on the 5V line. Counterfeit pico worked but I can't honestly recommend.
What you can do is get a small flex atx and de-case it. Then go to GitHub page and load an Arduino pro micro with the firmware.
Cut the wires from dead power supply and basically match it to ATX. Trim the wires and match the correct voltage to the original stock wires. You need to use the BEEP maintenance manuals as a guide as it gives you the proper ones.
PS-on, OS-off, 5V standby, power on/off wires need to be soldered to pro micro. Then cover it in tape.
Be careful as I remember the 5V and 12V wires I think are both brown. You need to follow the scheme in the maintenance manuals that Hota-san scanned for me.
I have looked at that book, but it is in Japanese, I do not understand it, or is it that I am very dummy
Quote from: fidelware on October 30, 2021, 12:21:53 AMQuote from: Cyothevile on October 27, 2021, 05:52:16 AMQuote from: fidelware on October 26, 2021, 04:26:50 PMHello everyone, I have won an FM Towns Fresh in Buyee, and I would like to update its PSU. the project of the new pcb continues?
I wasn't able to find a pico that pushes enough power on the 5V line. Counterfeit pico worked but I can't honestly recommend.
What you can do is get a small flex atx and de-case it. Then go to GitHub page and load an Arduino pro micro with the firmware.
Cut the wires from dead power supply and basically match it to ATX. Trim the wires and match the correct voltage to the original stock wires. You need to use the BEEP maintenance manuals as a guide as it gives you the proper ones.
PS-on, OS-off, 5V standby, power on/off wires need to be soldered to pro micro. Then cover it in tape.
Be careful as I remember the 5V and 12V wires I think are both brown. You need to follow the scheme in the maintenance manuals that Hota-san scanned for me.
I have looked at that book, but it is in Japanese, I do not understand it, or is it that I am very dummy
Ok.
When you get your desktop take the power supply out completely and show a photo.
Thank you Cyothevile for your work
I've repaired 2 of my towns
Guys if needed i have for sale 3 1 PCB and 1 Arduino pre-programmed, just PM me.
(https://live.staticflickr.com/65535/51637217757_588361b962_c.jpg)
(https://live.staticflickr.com/65535/51638897930_0e5c6cdba2_c.jpg)
Quote from: Cyothevile on October 30, 2021, 12:25:25 AMQuote from: fidelware on October 30, 2021, 12:21:53 AMQuote from: Cyothevile on October 27, 2021, 05:52:16 AMQuote from: fidelware on October 26, 2021, 04:26:50 PMHello everyone, I have won an FM Towns Fresh in Buyee, and I would like to update its PSU. the project of the new pcb continues?
I wasn't able to find a pico that pushes enough power on the 5V line. Counterfeit pico worked but I can't honestly recommend.
What you can do is get a small flex atx and de-case it. Then go to GitHub page and load an Arduino pro micro with the firmware.
Cut the wires from dead power supply and basically match it to ATX. Trim the wires and match the correct voltage to the original stock wires. You need to use the BEEP maintenance manuals as a guide as it gives you the proper ones.
PS-on, OS-off, 5V standby, power on/off wires need to be soldered to pro micro. Then cover it in tape.
Be careful as I remember the 5V and 12V wires I think are both brown. You need to follow the scheme in the maintenance manuals that Hota-san scanned for me.
I have looked at that book, but it is in Japanese, I do not understand it, or is it that I am very dummy
Ok.
When you get your desktop take the power supply out completely and show a photo.
look at this website, there is a photo
http://hanihanisayoko.seesaa.net/article/431188283.html
Friend there is two types of "fresh" type desktops. 4 slot expansion and 3 slot expansion.
If you have a photo of the desktop with the top lid off, I can better give advice.
(https://i.postimg.cc/tsNLp3Qn/124-D2145-C0-A9-433-A-AFFA-227-DA32-DE0-AF.jpg) (https://postimg.cc/tsNLp3Qn)
(https://i.postimg.cc/LqywZmsH/8299-E18-C-5-CFD-4-CFF-926-A-613-F52577057.jpg) (https://postimg.cc/LqywZmsH)
(https://i.postimg.cc/94XsMDC8/DC9-F9-B87-3-BD4-4-EA1-9805-2-E415633-D441.jpg) (https://postimg.cc/94XsMDC8)
(https://i.postimg.cc/tsNLp3Qn/124-D2145-C0-A9-433-A-AFFA-227-DA32-DE0-AF.jpg) (https://postimg.cc/tsNLp3Qn)
(https://i.postimg.cc/LqywZmsH/8299-E18-C-5-CFD-4-CFF-926-A-613-F52577057.jpg) (https://postimg.cc/LqywZmsH)
(https://i.postimg.cc/94XsMDC8/DC9-F9-B87-3-BD4-4-EA1-9805-2-E415633-D441.jpg) (https://postimg.cc/94XsMDC8)
Friend there is a connector that connects to computer motherboard.
Can you show us a photo of that? That is more critical.
it looks like same as a HR one
i have replaced my entire HR PSU with a (poor) Pico PSU + Arananet adapter. It works fine but yes I'm waiting for another CYO new project :)
There are 3 different desktop power cards and they are DIFFERENT. Don't assume until you check the connector and specifically color order of wires. Towns for some reason like to mix up brown wires which have 12V and 5V.
I don't be making a power card for desktops. I learned a lot from the failed project though. Specifically there isn't a pico that outputs enough power on 5V rail. Fake/clone pico can output enough current in my tests but I can't recommend fake pico. I don't use fake pico those are shit.
I have been meaning to make a photo guide of ATX conversion and use my HR100 as the example. I've just been really busy with other projects but a clever person again can use my Arduino pro micro script and a flexATX, taken out of its case and fit it inside the stock desktops PSU case. It's the same Arduino code that works perfect on the tower models. I must say though a flexATX won't fit inside a Pentium desktop.
How much power does the towns desktops need on the 5V rail?
Quote from: kamiboy on November 26, 2021, 08:35:48 PMHow much power does the towns desktops need on the 5V rail?
There are so many different ones I didn't even attempt to lock onto that.
I have updated the Tower card and added mounting holes specifically for using a slightly cheaper AC/DC converter such as the EPS-120-12. Any converter in a 2x4 (inches) form factor will fit. Also reposition it closer to AC cable.
I still need to verify the measurements of the original card (which I don't have anymore RIP) specifically the screw holes. Heard a report here and one other spot that it's troublesome and filing the holes was required. If anyone here would like to give me a dead tower PSU out of charity I would appreciate it.
https://github.com/cyo-the-vile/FMT-ATX-TOWER
I will update it one more time in a few weeks and have a store online to sell some cards.
If there is demand for a GEN1 card I will revisit that.
Update: Modified Gen 1 card requirements and sizing. Now the card is 2 layer but requires expensive ACDC converter. Untested. If you plan to use this I can help in the assembly via DMs so you don't fry the pc
Thanks for sharing all of this. My CX20 worked beautifully for a few hours after I recapped it. Then the next day it would no longer turn on, and I found a toasted resistor on the power supply. I'm going to order all of the parts and give this a try.
Quote from: Cyothevile on August 09, 2022, 04:31:43 AMUpdate: Modified Gen 1 card requirements and sizing. Now the card is 2 layer but requires expensive ACDC converter. Untested. If you plan to use this I can help in the assembly via DMs so you don't fry the pc
Hey Cyo!
I've had your (updated) Gen1 card made at JLCPCB, I have a PicoPSU (original) and a Meanwell 12V ACDC that I've already used before successfully on X68000s.
photo_2024-09-04_14-57-33.jpg
I'll be following your guide here:
https://ascendance.systems/2021/06/01/fm-towns-power-supply-generation-1/
Do you have anything to add other than the post above and github?
Thanks in advance
Gen1 PSU (almost) fully built. Triple-checked the pins on the Centronics-14 connector to the motherboard.
photo_2024-09-04_20-52-45.jpg
Just waiting for the Arduino Pro Micro (I had several Minis, no Micros) to arrive tomorrow, program it, and see how it goes. So far so good.
Cheers
Hi all,
I m looking to order 5 board to build a PSU for my FMT 2F in the coming days, if anyone is having spare board please let me know, I m happy to buy it
Quote from: Cyothevile on August 09, 2022, 04:31:43 AMI have updated the Tower card and added mounting holes specifically for using a slightly cheaper AC/DC converter such as the EPS-120-12. Any converter in a 2x4 (inches) form factor will fit. Also reposition it closer to AC cable.
I still need to verify the measurements of the original card (which I don't have anymore RIP) specifically the screw holes. Heard a report here and one other spot that it's troublesome and filing the holes was required. If anyone here would like to give me a dead tower PSU out of charity I would appreciate it.
https://github.com/cyo-the-vile/FMT-ATX-TOWER
I will update it one more time in a few weeks and have a store online to sell some cards.
If there is demand for a GEN1 card I will revisit that.
Update: Modified Gen 1 card requirements and sizing. Now the card is 2 layer but requires expensive ACDC converter. Untested. If you plan to use this I can help in the assembly via DMs so you don't fry the pc
I downloaded your Kicad files and made some modifications for a custom version of the PSU for my own use. I decided to use the Meanwell RM-90-12 AC/DC converter, which is only 80Watt and swapped the Arduino for an Attiny85. The reasons for the changes are not exactly what I would call, rational, but it is more of an experiment anyway.
I originally wanted a ATtiny4 since it has the fewest number of input/output pins but I don't think that series can be programmed using Aruduino code and I wasn't keen on trying to figure out how to code for it. There is no benefit to using an ATtiny really, but I feel an Arduino is a bit overkill for just on/off functionality. I actually wanted to see if I could make the on/off circuit using old fashioned IC's such as flip flops and and gates, but after a bit of research I think that would have been too much work to get the same functionality.
The RM-90-12 is quite cheap, but I want it mainly because it is a neat self contained module. I originally wanted to just circumvent the AC/DC + PICO combo and use several TRACO modules plus the optocoupler from the original PSU, but the cost would have been very high.
80W might be too little for what the TOWNS might pull out of the PICO, though...
Anyway, I'll report back how things go.
(https://i.ibb.co/LxBHStM/Screenshot-2024-10-15-at-12-07-21.png)
Well, I think I am just about done with the modifications. I decided to repurpose the relay to enable the switching on/off of the power output port from my 20F PSU.
However, that should obviously not be used when connecting to 220V so I added a jumper to disable the relay functionality.
I also incorporated the fuse and three input filter caps that were connected to the voltage input from the old board. Not sure they do anything useful on this modern system, but hey, they are optional, so they can be skipped.
I also added in the three screw holes in the middle of the board. I am certain my measurements will be off by a bit and some things are likely not optimally placed, but I think getting it right on the first try is not realistic. I'll try to order a print and see what happens.
I got the idea to print out the PCB layout and see how things lined up. To my surprise the board width seemed to be off by 2 mm on one side, which is fine, but all the screw holes also seemed off by degrees.
Now, I am not 100% sure I can trust the print, but after careful measuring of the board I am convinced that the print is an accurate representation of where things will go on the PCB. So I just repeatedly adjusted the screw holes and printed out the results for comparison. After 10 or so iterations I think I have them more or less dialled in now.
There are these metal pegs that the PCM falls into and the tolerances there are quite tight, of they don't light up exactly I think the PCB won't go into place. Additionally the alignment of the exit port is very crucial, and on my model it slides into place and I think the pins need to align up exactly or it prolly won't slot into place.
Can anyone with a later revision tower PCB attest to how well the screw holes, metal pegs etc. lined up in their case?
Some early responses mentioned needing to file down holes, but I am wondering whether my adjustments are just screwing up an already perfectly dialled in placement or not.
Seems getting the mounting hole placements right might be quite tricky...
Quote from: kamiboy on October 16, 2024, 07:14:53 PMI got the idea to print out the PCB layout and see how things lined up. To my surprise the board width seemed to be off by 2 mm on one side, which is fine, but all the screw holes also seemed off by degrees.
Now, I am not 100% sure I can trust the print, but after careful measuring of the board I am convinced that the print is an accurate representation of where things will go on the PCB. So I just repeatedly adjusted the screw holes and printed out the results for comparison. After 10 or so iterations I think I have them more or less dialled in now.
There are these metal pegs that the PCM falls into and the tolerances there are quite tight, of they don't light up exactly I think the PCB won't go into place. Additionally the alignment of the exit port is very crucial, and on my model it slides into place and I think the pins need to align up exactly or it prolly won't slot into place.
Can anyone with a later revision tower PCB attest to how well the screw holes, metal pegs etc. lined up in their case?
Some early responses mentioned needing to file down holes, but I am wondering whether my adjustments are just screwing up an already perfectly dialled in placement or not.
Seems getting the mounting hole placements right might be quite tricky...
Those mounting hole placements are an extreme pain in the ass and I never got it right. Optimally, you would want to desolder every single component on the PSU card and scan it. Upload it as a graphic in kicad and move the mounting holes accordingly. Me using a caliper isnt perfect as usually only ~4 mounting screws work properly and sanely.
If you do end up making a sane card that has mounting holes that arent insane please push a commit so I can update it.
I did get the metal post locations more or less correct, except for one which ended up being off by a millimetre. Luckily the metal posts on my housing can be bent a bit to make them fit, which I did and fit it did.
I have soldered just about everything in but have yet to actually test the PSU as I need to find a way to program the ATtiny85 with the Arduino code. I have a USB programmer but it seems to require a Windows machine to work, which I do not have nor can access at the moment.
In any regards, I won't upload my modified files to the GitHub repository as I did the modifications in a haphazard way because I was not familiar with the software. So I am afraid I might break something if they are just uploaded as is. However, the files are attached here to do with as you please. Perhaps you can copy over the post locations from it.
What's the name of the white connector?
I'd like to keep my original PSU intact, and assemble a new one with all new parts including the connector.
Thanks!
Quote from: amazin on January 29, 2025, 12:59:32 AMWhat's the name of the white connector?
Hirose PCN13-44S-2.54DS(71)
Quote from: hiker on February 09, 2025, 02:27:45 PMHirose PCN13-44S-2.54DS(71)
Thanks ever so much, Hiker!
I'm about to get PCB way to make this for me. I've not used them before but looks like the minimum order size it 5... Anyone in the UK need one of these?
Hey
@Clueless I'm in the UK too, I could send you one of my boards, as I have extras... Just need to find where I put them, but I certainly have a spare.
Do you wanna share 1/5 of the costs?
Cheers
Quote from: amazin on February 12, 2025, 02:02:45 AMHey @Clueless I'm in the UK too, I could send you one of my boards, as I have extras... Just need to find where I put them, but I certainly have a spare.
Do you wanna share 1/5 of the costs?
Cheers
Thank you for the kind offer
@amazin, I got this message too late, I was too keen to buy as my machines on it's way to me, and I want to hit the ground running :D
If you've any other spare parts, or information on where to get the essentials a new FM Towns 2 owner might need I'd really appreciate that also (e.g: FDD drive belts, anywhere selling the ODE's, etc).
Thanks again
@amazin
ah okay, no worries... what model exactly you got, ping me if you need anything.
A final important update to my 20F PSU version. Wouldn't you know, I made a whole bunch of stupid mistakes.
1. The AC mains to 12V DC PSU unit was inserted the other way around in the schematics.
2. The PSU fan pins had been switched around.
3. I had used the wrong (smaller) footprint for the ATtiny in the schematics.
4. The ATtiny code had switched the Power Button and OS traces around.
In regards to programming an ATtiny for use on the board, I found buying the Digispark USB ATtiny thingy to work well. It is quite cheap, can be programmed directly by plugging into a computer and using the Arduino software, with appropriate module installed. Then I just soldered the ATtiny off of the USB board and soldered on the PSU.
The above are now fixed in the attached files.
Since printing the first revision boards cost me dearly I chose not to get the updated one made, and instead I worked around the mistakes, and can confirm it works in my 20F.
The old girl has life once again, after many, many years. Now I can shove it back into storage, never to use it again, since I have other fully functioning Towns models.
Quote from: Cyothevile on January 06, 2021, 01:07:42 AMI have made some progress with a Tower power supply replacement. The 44 pin connector is not proprietary and is a modern sourceable part and it's still manufactured. The design will be open sourced once it works and I have a reseller willing to sell them once working so people can get them. The end state is a beginner level soldering installable replacement for these computers. We know those tower PSUs are a pain even after a recap they seem to die. This has happened to me twice.
At this time my board simply functions as an ATX adaptor where you need the second switch in the back for it to function. However I'm exploring circuits at this time to turn the PSU on with the original power button and an operating system shutdown function through townsOS. This would place this PSU as a direct 1:1 replacement in terms of functionality.
A shorter version without the 12V DC converter is also possible if you can fit an ATX inside the original metal shielding. For the 220V countries this means you won't require a step down converter.
Attached is photo of my current board. The circuit onboard doesn't work. I have the proper pin out for the 44 pin backplane connector and the computer does turn on if you force the power on. However the original power button isn't working to turn it on. I attempted a latching circuit and unfortunately it isn't enough. I'll be attempting a new circuit later this week.
For those with electrical engineering experience I would love some input with this. If this project is completed a solution can be made for the desktops as well with the same circuit if it works for towers. Towns seems to use two different power supplies all together.
Hi Cyo, will you be considering to do a Marty PSU? The guy who came up with it years ago just vanished.
Not much infos regarding the Marty PSUs, appreciate if you can advise me on it.
There are some complications regarding using same parts to do a Marty version, namely that the Marty runs on different voltages, I think +/- 9V instead of 12V. But it doesn't have soft power so that part is easier.
The original project thread is on shmups. It seems the author stopped being active around 2021, but has had two posts made there in 2025. Maybe try and send him a private message.
Be warned that buying the parts for his design won't be cheap. Those Traco modules were quite expensive back when I got them.
https://shmups.system11.org/viewtopic.php?t=66562
Quote from: kamiboy on May 08, 2025, 04:11:52 AMThe original project thread is on shmups. It seems the author stopped being active around 2021, but has had two posts made there in 2025. Maybe try and send him a private message.
Be warned that buying the parts for his design won't be cheap. Those Traco modules were quite expensive back when I got them.
https://shmups.system11.org/viewtopic.php?t=66562
Yes I saw his "recent" post but I'm never active there so I cant msg him unless I make some posts to qualify XD..
An expensive option is better than a dead console I supposed...
Now I need to find my multimeter to make sure its the psu and not my board thats dead, its always missing when I need it...
Quote from: Hareluya on May 07, 2025, 07:16:15 AMQuote from: Cyothevile on January 06, 2021, 01:07:42 AMI have made some progress with a Tower power supply replacement. The 44 pin connector is not proprietary and is a modern sourceable part and it's still manufactured. The design will be open sourced once it works and I have a reseller willing to sell them once working so people can get them. The end state is a beginner level soldering installable replacement for these computers. We know those tower PSUs are a pain even after a recap they seem to die. This has happened to me twice.
At this time my board simply functions as an ATX adaptor where you need the second switch in the back for it to function. However I'm exploring circuits at this time to turn the PSU on with the original power button and an operating system shutdown function through townsOS. This would place this PSU as a direct 1:1 replacement in terms of functionality.
A shorter version without the 12V DC converter is also possible if you can fit an ATX inside the original metal shielding. For the 220V countries this means you won't require a step down converter.
Attached is photo of my current board. The circuit onboard doesn't work. I have the proper pin out for the 44 pin backplane connector and the computer does turn on if you force the power on. However the original power button isn't working to turn it on. I attempted a latching circuit and unfortunately it isn't enough. I'll be attempting a new circuit later this week.
For those with electrical engineering experience I would love some input with this. If this project is completed a solution can be made for the desktops as well with the same circuit if it works for towers. Towns seems to use two different power supplies all together.
Hi Cyo, will you be considering to do a Marty PSU? The guy who came up with it years ago just vanished.
Not much infos regarding the Marty PSUs, appreciate if you can advise me on it.
I could make something thats drop-in yes. However I havent found many Marty PSU cards that were unrepairable. They usually just need new capacitors.
Is there really such a demand for a card? Im seriously asking. I can do it no problem. Im just curious on the need thats all.
A potential benefit of swapping PSU's even if the stock one is not broken, is avoiding the need for stepdown converter for people in 220v countries. That is why I replaced my PSU, even though there was nothing wrong with it.
Quote from: kamiboy on May 23, 2025, 07:55:34 PMA potential benefit of swapping PSU's even if the stock one is not broken, is avoiding the need for stepdown converter for people in 220v countries. That is why I replaced my PSU, even though there was nothing wrong with it.
It makes sense dont get me wrong. I like to keep these old computers and consoles as original as functionally possible. But if there is such a drive for a replacement, I can make one and test it and throw it on github. It will be expensive though, and to be honest, I would hold it until I sold a few units (maybe like ~5 units) to pay for R&D / recoup the cash I threw into getting it working.
If the connector type could be identified and a cable was floating around in bulk, that would make things nicer. Otherwise this project would require soldiering. I think we have been at these forums for a long time and know that the average Marty user is not always an average japanese pc user.
If a compatible mating cable/connector can be identified, I feel comfortable starting this quickly.