FM-Towns CD drive replacement

Started by eidis, June 06, 2014, 03:36:30 PM

Previous topic - Next topic

eidis

 Hi Guys !

The FM-Towns and FM-Towns Marty are notorious for having worn out lasers and legend has it that until now no one was able to find a working replacement so it looks like the next best way to solve this legendary problem would be to connect a generic CD or DVD to the system. Caius, let's make it happen ! ;)

The FM-Towns features a 40pin CD rom connector which can be mistaken for IDE but it is not. Back in the early 90's before ATAPI CD-ROMs became the industry standard there were proprietary interfaces and usually they were available on ISA soundcards. Some of them are:

Gravis Ultrasound MAX:

    Panasonic   40 pin connector
    Mitsumi       40 pin connector
    Sony           34 pin connector
   

Sound Blaster Pro 2:

    CT1610, SCSI
    CT1620, LMSI
    CT1690, Sony
    CT2600, Mitsumi

Here are some interesting links regarding the previously mentioned interfaces.

List of proprietary CD-ROM drives:
http://www.tldp.org/HOWTO/CDROM-HOWTO/x97.html

Pinouts:
========

Panasonic CD-ROM pinout
http://old.pinouts.ru/Storage/CdRomPanasonic_pinout.shtml

Mitsumi CD-ROM pinout
http://old.pinouts.ru/Storage/CdRomMitsumi_pinout.shtml

Sony CD-ROM pinout
http://old.pinouts.ru/Storage/CdRomSony_pinout.shtml

ATA / IDE pinout
http://pinouts.ru/HD/AtaInternal_pinout.shtml

Slimline CD-ROM connector pinout
http://pinouts.ru/Storage/slimline_cdrom_pinout.shtml

Misc info:
==========

A Home Built (almost) Panasonic/MKE/CR56x CD-ROM Interface:
http://www.chiark.greenend.org.uk/~theom/electronics/cdr56x.html

About Panasonic MKE CD-ROM cable:
http://www.sysopt.com/showthread.php?9681-Panasonic-MKE-CD-ROM-interface

In depth review of the Sony CDU33A-01. Viewer discretion is advised - page contains hardware pron:
http://goughlui.com/?p=293

We know that FM-Towns CD-Rom has 40 pins so that immediately disqualifies Sony interface. The Panasonic and Mitsumi interfaces both have 40 pins and luckily the GND signal goes to different pins so it could be possible to deduct which one is used by doing continuity testing on the Fm-Towns CD-ROM and HDD riser card. However, there is a chance that Fujitsu has used a completely proprietary interface or it could be a Sony or SCSI interface in disguise.

Has anyone tried something very dangerous as connecting a Panasonic or Mitsumi proprietary CD-ROM drive to FM-Towns ? Please be aware that it might work or it might damage your computer beyond repair.

Keep the scene alive !
Eidis

P.S. Could it be possible to connect the FM-TOWNS CD-ROM to PC via soundcard ?
   
X68000 personal computer is called, "X68K" or "no good good" is called, is the PC that are loved by many people today.

jetblue

hi,ive done some work on the marty and post about it here. currently im trying other panasonic lasers on it to see if it takes. a laser similar to the one on it has but i fear it wont work.

ive worked on fm towns before, the round vertical drive unit,and it has a common panasonic laser. i always thought the future for the fm towns would be like the 3do and amiga cd where a memory card interface would be invented eliminating the laser drive all together.
but a universal replacement would be most ideal. a common panasonic drive of the era is this:

http://www.ebay.com/itm/Panasonic-PCMCIA-SCSI-CD-ROM-KXL-D720-/251350066007?pt=US_CD_DVD_Blu_Ray_Drives&hash=item3a85a1a357

a Panasonic PCMCIA SCSI CD-ROM KXL-D720
ive seen others messing with vintage pc's finding a way to integrate that unit in them one way or another. i read its easier than the others. not sure how and why but may be worth looking into. il dig up more of my notes and share.

good luck on this worthy venture.

caius

Quote from: jetblue on June 07, 2014, 12:47:10 PM
hi,ive done some work on the marty and post about it here. currently im trying other panasonic lasers on it to see if it takes. a laser similar to the one on it has but i fear it wont work.

ive worked on fm towns before, the round vertical drive unit,and it has a common panasonic laser. i always thought the future for the fm towns would be like the 3do and amiga cd where a memory card interface would be invented eliminating the laser drive all together.
but a universal replacement would be most ideal. a common panasonic drive of the era is this:

http://www.ebay.com/itm/Panasonic-PCMCIA-SCSI-CD-ROM-KXL-D720-/251350066007?pt=US_CD_DVD_Blu_Ray_Drives&hash=item3a85a1a357

a Panasonic PCMCIA SCSI CD-ROM KXL-D720
ive seen others messing with vintage pc's finding a way to integrate that unit in them one way or another. i read its easier than the others. not sure how and why but may be worth looking into. il dig up more of my notes and share.

good luck on this worthy venture.

Hi, I read your adventure with Marty laser pickup.I think RAE0170Z laser is just an invention and never existed.. :).Laser pickup in FM-TOWNS pc and Marty consoles is the same and it's a proprietary one.
Regarding the Panasonic PCMCIA SCSI CD-ROM, for sure it can work on FM-TOWNS wit the needed drivers but , sadly, you cannot boot from it so it's useless to launch CD based software.

jetblue

#3
that panasonic drive i remember reading it has the drivers in the pcmcia connector so when you plug it in the pc will read it automatic,something like that but im not sure 100% if that's what i read. i picked one up strictly for the marty to plug in but i was to do that in tandem with the martys processor upgrade. i was hoping when i clipped on the upgrade it would activate some factory recalibration then recognize the drive but getting the upgrade chip is expensive and i haven't saved up for it.

heres more notes that may be helpful. il be working on the fm towns marty laser replacement these next weeks but il post that in my old thread but heres what i never posted about the vertical drive model of fm towns,hope it helps:

FMTowns model 2f
https://www.flickr.com/photos/edpeixoto/sets/72157629970925899/
my replacement:
http://www.vcdpickup.com/panasonic.files/Rae0111z.jpg
pulled from a technics stand alone cd player model SL-PG 300,made in 1991.  Rae0111z model laser. looked online for a new laser but could not find.
http://img.photobucket.com/albums/v238/jetbue7/IMG_0217.jpg
http://img.photobucket.com/albums/v238/jetbue7/IMG_0223.jpg

caius

#4
Thanks for sharing your infos.
Regarding the PCMCIA Panasonic CD-ROM drive, do you think its internal drivers are compatible also with FM-TOWNS?
About the RAE0111Z, did you succesfully replace the FM-TOWNS 2F drive with  this assembly?Anyway, the pickup laser is very similar to the FM-TOWNS and Marty one.

jetblue

its been over 5 years and i lost contact with that customer in argentina but last i heard it worked but his power supply died on him so he was stalled from stress testing the laser. i have another laser i think if we can find a volunteer.

caius

I think RAE0111Z is the part name of the whole mechanism assembly so I was wondering which is the exact model of laser pickup in it.Anyway, I'll try to get this and test it on my FM-TOWNS machines (they both have Matsushita EBP504 CD-ROM).

P.S.
I think it can also fit on Marty consoles.

Tw3ek

Quote from: jetblue on June 11, 2014, 05:27:28 AM
its been over 5 years and i lost contact with that customer in argentina but last i heard it worked but his power supply died on him so he was stalled from stress testing the laser. i have another laser i think if we can find a volunteer.

I actually have an FM Towns 2F model on the way with a dead laser if you were still seeking volunteers. Everything else works fine, just issue with the CD-Rom drive.

caius

Quote from: Tw3ek on July 08, 2014, 05:40:53 AM
I actually have an FM Towns 2F model on the way with a dead laser if you were still seeking volunteers. Everything else works fine, just issue with the CD-Rom drive.

OK, keep us informed about.

Tw3ek

The FM-Towns with the laser issue is now in my possession. Everything else appears to work fine, but when a CD is inserted into the Towns, it boots into Towns OS, then has issues reading the disc. The spindle appears to be somewhat sticky (it looks like the protective material on there melted or something) so I am wondering if it is in fact not a laser issue at all but instead an issue with the disc getting stuck on the spindle?

SuperDeadite

Sounds like the drive closed switch has gone bad.  If you have an older Towns where the ribbon cables are soldered, it is quite a project.  BlueBMW fixed a Towns with this issue, he's the one to talk to.

Tw3ek

Quote from: SuperDeadite on August 25, 2014, 02:51:10 PM
Sounds like the drive closed switch has gone bad.  If you have an older Towns where the ribbon cables are soldered, it is quite a project.  BlueBMW fixed a Towns with this issue, he's the one to talk to.

Yes, it is an older Towns (Model 2F). Thanks for the help!

BlueBMW

There are actually two drive closed / open switches.  One is a physical switch that is tripped by the door itself and the other is behind the button used to open the drive.  Basically when you hit the button to open the drive it trips that switch so that the cdrom stops before the lid actually opens.  The switches run in series and if either one isnt working right the drive wont read.  I had to disassemble both switches and clean their internal contacts.  One of them i had to split open to service as it was not designed to be serviced.  I had to glue it back together.

RetroRepair

I'll be uploading a repair video in the next day or two on how I repaired a UX20 drive. That was not an easy task, just about everything that could have been wrong with it, WAS wrong with it. I'm surprised I managed to get it working again.

For those just wanting a total replacement, here's a link to a seller on Aliexpress that sells them:

http://www.aliexpress.com/item/RAE0111Z-RAE-0111Z-Songxia-With-shell/1511028273.html

I believe that will work for the tower and all in one systems, not sure about the Marty but I'd wager it's the same.

eidis

 Hi RetroRepair !

Congratulations on a job well done ! Looking forward to the tutorial.

Keep the scene alive !
Eidis
X68000 personal computer is called, "X68K" or "no good good" is called, is the PC that are loved by many people today.

RetroRepair

Well it's not so much a tutorial, just a few tips.

It will be here once it's done processing: http://youtu.be/KUdre4a2Psg

I'll list the problems and steps taken to repair it here.

First thing I noticed was the spindle. When I took it apart, it lifted off the motor with the top assembly that's supposed to hold it in place. It was very loose on there so initially I put a bit of blutac on there to keep it in place but in the end I had to use superglue to keep it on. Do NOT push it all the way down, it needs to be about 1mm off the base of the motor.

To prevent this happening again, I added two layers of electrical tape to the magnet in the top of the drive which holds a padded plate on the disc to stabilise it when it's spinning. It's far too powerful and probably why the spindle was worked loose in the first place.

Luckily, before I did this I noticed the original drive motor was rock solid so had burned itself out. I replaced it with another motor from an old CD-Rom drive I had laying around. It's a very common type.

By this point the drive did move the disc, however was still not reading. After cleaning the lens with isopropanol alcohol I looked at the laser diode itself. As stated above, it's a Panasonic RAE0111Z and can be purchased here:

http://www.aliexpress.com/item/RAE0111Z-RAE-0111Z-Songxia-With-shell/1511028273.html

There is a small potentiometer on the back of the laser (like most laser diodes) which will increase the strength of the laser, in this case with anti clockwise turns. I would recommend making very small adjustments (about 1/8 of a turn) until your disc starts to read. In my case, I needed to turn it a fair bit more, almost a full turn and a half. At this point I could almost get it reading and once or twice (out of 20 or so trys) it did read the disc but not for very long.

The final step was to replace the capacitors on the drive board under the CD drive. As with most electronics this age, the caps were dried out and had started to leak. They didn't look bad and you would not have guessed there was anything wrong with them at first glance but as I removed them, I could see a few had indeed leaked. Also be aware that some of these are BP (bi-polar) capacitors, they are easy to spot as they don't have the negative strip down the side and have BP written on them.

So finally, success! It took a few days to to it but I'm more than happy with the results, reads first time every time now!

I'm still going to replace it anyway, at least when it starts to really fail. The laser is set about as high as it can go now so it's only a matter of time before it dies completely and it's best to grab these laser units while they are still available!

fredohenriquez

Hello guys,

Do you think this laser replacement will work with a FM Towns HB53 model?

Cheers!

yukin

My cd drive won't spin the cd anymore, i order the RAE0111Z laser kit. Just want to know if we need to make adjustment on it after the swap of the laser pickup? Like Re allign or adjust speed?

dankcomputing

Quote from: BlueBMW on August 26, 2014, 01:27:31 AMThere are actually two drive closed / open switches.  One is a physical switch that is tripped by the door itself and the other is behind the button used to open the drive.  Basically when you hit the button to open the drive it trips that switch so that the cdrom stops before the lid actually opens.  The switches run in series and if either one isnt working right the drive wont read.  I had to disassemble both switches and clean their internal contacts.  One of them i had to split open to service as it was not designed to be serviced.  I had to glue it back together.

I've had this problem on my machine and I was able to salvage a compatible door button switch from a dead 3.5 floppy drive. Floppy drives will use these switches to detect whether a disk is write protected, high density, or present in the drive at all. Only problem is the newer FDDs tend to use the double version of the switch; FM Towns needs the single plunger version. This makes it harder to find.

The door closed switch is a more common type of switch and it seems to be present in a few of the CD drives I've opened up over the years. Probably doesn't need to be replaced as much as the door button switch.

I've attached a couple of photos of the switches. It's almost impossible to get part numbers off of these switches; does anyone know of a source for getting them new/NOS?

FM Towns CD Drive Button Switch 2.JPG
FM Towns CD Drive Button Switch 1.JPG
FM Towns CD Drive Door Switch 2.JPG
FM Towns CD Drive Door Switch 1.JPG

watto

The little door switches I had no luck finding the equivalent on Mouser, etc.  I actually picked up these from eBay: https://www.ebay.co.uk/itm/5-Pcs-DC-50V-1A-SPST-Momentary-Micro-Miniature-Switch-Green-for-Camera/362278586324

What I got worked as a replacement in my white Towns CD drive, YMMV.

fidelware

hi, has anyone found where to buy the other micro switch?

mattsoft

Recently picked up a UX20 with a, guess what, non-functioning CD-ROM drive. Well, it sometimes works, but mostly not. When I put a CD in the drive, the CD lens makes 2 short moves but the spindle does nothing.

Recapped the CD board, no change. I replaced the CD pickup with a brand new one, no change. Removed the spindle motor and lubricated the motor, then applied +5VDC to spin/lubricate it; it spun just fine, but still no change when re-installed.

Sometimes when I insert the CD, if I give the CD a helping hand and spin it, it will startup and work. Maybe not enough voltage getting to the spindle motor?

Should the spindle spin at least a little? Like maybe a single rotation, even if the CD pickup is bad?

Jehuty

No, when the laser "doesn´t find" the CD it won´t spin up.
So i think your motor is fine. It´s the laser pickup.
Normaly the lens would search 2 or 3 times and if it gets the cd the motor spins up.
But when not it won´t spin up.
With what pickup did you replace the old one ?
Aergan postet that the laser from an Technics CH505 should fit.
I replaced the laser in one 20F and one CX20 with that from an ch505 and both worked, not 100% but 80 to 90%. Depending on the disc.

Look on the PCB, what potis are on the UX Drive ? The Grey Tower got 6 on the pcb.

But - don´t touch the Laser Pot on the pickup, it will destroy the laser immediatly !

mattsoft

Quote from: Jehuty on February 28, 2022, 02:41:12 AMNo, when the laser "doesn´t find" the CD it won´t spin up.
So i think your motor is fine. It´s the laser pickup.
Normaly the lens would search 2 or 3 times and if it gets the cd the motor spins up.
But when not it won´t spin up.
With what pickup did you replace the old one ?
Aergan postet that the laser from an Technics CH505 should fit.
I replaced the laser in one 20F and one CX20 with that from an ch505 and both worked, not 100% but 80 to 90%. Depending on the disc.

Look on the PCB, what potis are on the UX Drive ? The Grey Tower got 6 on the pcb.

But - don´t touch the Laser Pot on the pickup, it will destroy the laser immediatly !

Yup, found a NOS source on eBay for the CH505 pickups. Haven't touched any POTs, will check the POTs on the CD board, I think there are like 4 or 5.

mattsoft

#24
Some more experimenting...if I put a disc in, it won't read. But if I press down on the disc a little in the drive, it spins up and reads! I wonder if making a spacer to force that top spindle under magnet downward would help? It appears that disc is just not the right distance to the lens to get sensed! UGH!

EDIT: tried raising the height of the spindle platter by 1mm or so, didn't work. Tried lowering the height of the top magnet platter a couple mm, didn't work.

It reads reliably with an original disc if I just push down slightly on the disc after it's in the drive -- this seams to allow the laser pickup to see the disc and start the spin.

With CDRs, the same method also works, but is slightly less reliable. So even with the new laser pickup, it's having a hard time seeing the disc and starting up. :(

mattsoft

Yeah, there are 6 pots on the CD board. I dare not touch any of them as they are not marked as to what they adjust.

mattsoft

Just in case this helps anyone else, I've been playing with the 6 variable resistors (VR1-6) on the CD-ROM board of my UX20 using the guides here:

https://www.repairfaq.org/REPAIR/F_cdfaq7.html
https://www.repairfaq.org/sam/cdfaq.htm#cdgensap

VR1 PD.BAL -- photodiode balance (?)
VR2 TR.BAL -- tracking balance
VR3 F.GAIN -- focus gain
VR4 F.OFF -- focus gain
VR5 T.GAIN -- tracking gain
VR6 T.OFF -- tracking offset

Unfortunately I was not able to see any improvement, I could only make it worse.

Before you mess with these, make sure you mark the default locations (like with a pen).

Jehuty

yes these 6 you could play with and i think you must when you replaced the laser.
I played long time but can´t remeber for sure but i think Focus and tracking gain where the most important when the laser doesn´t find the cd. The others are for fine tuning.
Just try all in middle position and then in little steps the two gain in different direction.
One of them was to find the CD so the motor starts and on the other you can hear a little noise when the cd is spinning. So you have to turn a little bit back.

mattsoft

Quote from: Jehuty on March 04, 2022, 02:54:31 AMyes these 6 you could play with and i think you must when you replaced the laser.
I played long time but can´t remeber for sure but i think Focus and tracking gain where the most important when the laser doesn´t find the cd. The others are for fine tuning.
Just try all in middle position and then in little steps the two gain in different direction.
One of them was to find the CD so the motor starts and on the other you can hear a little noise when the cd is spinning. So you have to turn a little bit back.

Maybe I'll play with them a little more. I also found a Panasonic CD player on eBay for cheap (supposedly workin) that appears to have a compatible traverse deck that I might try swapping out incase the spindle or traversal motor are bad. I want this UX20 to work so bad! :)

mattsoft

Great news this afternoon. After lots of searching, I found that the Panasonic SL-PJ316 CD player has the exact same traverse deck as the UX20. Found a working one on eBay. Quick swap of the decks, and... it works! My UX20 is alive and working!

Jehuty

Now we have to find a replacement für the MA types

Cyothevile

Quote from: mattsoft on March 06, 2022, 08:24:13 AMGreat news this afternoon. After lots of searching, I found that the Panasonic SL-PJ316 CD player has the exact same traverse deck as the UX20. Found a working one on eBay. Quick swap of the decks, and... it works! My UX20 is alive and working!

Excellent news!

What lead you to conclude that was the proper CD player to cannibalize the laser from?

mattsoft

Was browsing Panasonic CD players from the same years as the FM Towns in the Sears Parts Direct catalog and came across this: https://www.searspartsdirect.com/model/2bbkapw0fh-000789/panasonic-slpj316-cd-player-parts

The diagram of the traverse deck looked identical to the UX20, so I took a chance and bought one off of eBay. Both motors, the entire mechanism, and laser are identical. Just had to swap the CD board and power wires, and the faceplate.


Cyothevile

Thank you Matt.

I might attempt to chase down a replacement mechanism for my HB Towns with a dead drive doing the same thing