Can anyone in the UK do a capacitor change for me?

[X-Col]

It's been 2 months and the electronics shop here still hasn't started the capacitor change on my Ace HD. Complaining that's it's a 'Big Job' and they would have to turn work down to do it.

It's not looking good, and I have destroyed old motherboards trying this myself. So just asking if there is anyone in the UK who could do this for me? The X68000is already disassembled, and I can send just the boards.

I would be very grateful and pay whatever you charge for the service, I just want my X68000 back 

X-Col

[eidis]

 Hi X-Col !

Why don't you want to learn how to solder ? It's not as hard as it might seem and you will hugely benefit from that skill in the future. If your X68000 is the twin tower type, then it will take a huge effort to damage it while replacing the capacitors. Those things are very robust.

Keep the scene alive !
Eidis

[X-Col]

I do a little soldering, but after I killed a MSX Turbo R, I lost a lot of confidence, and money!
I find it hard to remove these old capacitors without damaging the motherboard. The metal connections came off with the capacitors on my Turbo R. I was unable to repair the damage done.

Have you any tips/hints and I may give it a try?

[eidis]

 Hi X-Col !

I find it hard to remove these old capacitors without damaging the motherboard.

Don't worry, everything will be fine. With practice and patience you will master this skill. First of all tell me about your tools. What kink of soldering iron do you use and what is its wattage ? The key here is to use as small wattage as possible. That will help prevent delaminating the traces and damaging components while soldering. I personally use 16w 220v soldering iron for generic soldering and 8w 12v for very delicate work. (please see the attached picture)

The biggest mistake which beginners usually make is choosing a soldering iron with too large wattage. In such cases the components can be more easily overheated and pcb traces can get delaminated.

You will also need a soldering wick. Basically you put it on solder joint, heat it with soldering iron and it sucks up the solder. This is a must have. The best one which I have come across is Chem-Wik SIZE.100 10-5L. They are ESD safe and take the soldering to a whole new level.

Chem-Wik® Rosin SD
https://www.chemtronics.com/p-686-chem-wik-rosin-sd.aspx

More to come.....

Keep the scene alive !
Eidis

[X-Col]

Hi Eidis,

I have 2 soldering irons,
An unbranded 40W and an Antex 230V 15W
I have desoldering braid but it looks to be unbranded, so maybe not so good.

I have ordered the one you recommended 'although 7-5L' I think it's the same, just a little narrower.

What I,ve sometimes found is that the lower temperatures are not hot enough to melt 'old' solder. Is there a way to get old solder to melt again without raising the temperature and risk damaging the PCB?

X-Col

[eidis]

 Hi X-Col !

Your Antex 230V 15W soldering iron is exactly what you need. Please refrain from using the 40W iron even if you feel great temptation. You might want to consider investing in a soldering tip cleaner as well. It is not necessary but will make your work more pleasant.

DURATOOL  SH-1025  CLEANER, SOLDERING TIP
http://uk.farnell.com/duratool/sh-1025/cleaner-soldering-tip/dp/1467280

What I,ve sometimes found is that the lower temperatures are not hot enough to melt 'old' solder. Is there a way to get old solder to melt again without raising the temperature and risk damaging the PCB?

Yes, and it will surprise you how easy this method is. I usually use the following procedure when soldering.

1) Warm up the iron for approximately 5 minutes
2) Tin the head of the iron. This will clean the head, remove residue, oxidation and will allow more heat to be transferred.
3) Clean off the excess solder from the tip and add a little fresh solder to the joint with the old solder so that they melt. Do not heat one solder joint for more that 4 seconds to be on the absolutely safe side. Don't worry if you did not manage to achieve your goal in the 4 seconds. Let the joint cool for some 10 seconds and try again until you succeed. You will notice that once the old solder has combined with the fresh one it is much easier to melt it.

Electrolyte capacitors are big and have two massive legs which are separated wide apart (considering the advances of electronics) from each other and connected to the PCB by soldering joints. Your task is to heat one joint and at the same time gently bend the capacitor, which is on the other side, so that the heated leg will slide out of the joint. Do the same for other joint. Repeat the procedure until you have successfully removed the capacitor and remember about the 4 second rule.

Next, use soldering wick to remove any leftover solder from the two joints and uncover the holes where you will put the new capacitor. Use q-tip soaked in isopropyl alcohol, or some more gentle PCB cleaning agent, to clean the joints from accumulated residue and dirt.

Try finding an old PCB of some ancient broken electronic which you don't need, practice and feel free to ask any questions regarding this procedure.

P.S. Do not use broken stuff for practice which you might want to try repair after learning how to solder. You will be surprised how much a man is able to do with the right amount of motivation


More to come.....

Keep the scene alive !
Eidis

[SuperDeadite]

If you plan on doing this kind of thing on expensive hardware, do yourself a favor and get good quality tools.  For desoldering, get a Hakko 808.  You will not be disappointed.

[X-Col]

Hi SuperDeadite,

I've looked into your suggestion and it looks great! Just what the doctor ordered for desoldering.

Now to find one available in the UK!! Not managed to find any yet....

Update: looks like the FR-300 is the current model. I'll have a look for that one instead

Eidis, I will also practice on an old knackered Amiga 500 motherboard using your method. I'm not going to touch my X68000 until I'm more confident, and competent!

[eidis]

 Hi X-Col !

I will also practice on an old knackered Amiga 500 motherboard using your method

No, not the Amiga ! Please find something less valuable.

Keep the scene alive !
Eidis

[X-Col]

Don't panic Eidis, it's totally knackered, and missing most of the components.
I have several Amiga's as they are quite common in the UK.

I might re-cap my Amiga 500+ if all goes well with my X68000 project. 
My 2 Amiga 1200's were done a while ago and easy to do. I think that's why I got over confident and knackered my Turbo R. I was devastated 

I'll let you know how it goes my friends, and thanks for all your help 

[X-Col]

I have ordered a Hakko FR-300 from the States, thanks for the suggestion SuperDeadite!

Been playing about with the old motherboard and some great advice from Eidis, removed a few caps very cleanly. Just struggled a little with some of the larger caps. The solder just didn't want to melt.

After using Eidis' advice I removed them eventually without damaging the motherboard. So seems I'm improving   

One question, are the X68000 ACE motherboards single, double, or multi layer? Just so I have an idea what temperature I should set the Hakko desoldering tool to.

If I do this job successfully, I might try and fix my MSX 

[eidis]

 Hi X-Col !

Keep in mind that X68000 is not ROHS so the solder will have a lower melting temperature.

Restriction of Hazardous Substances Directive
http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

Keep the scene alive !
Eidis

[H68k]

I found adding a bit more solder to what's on the leg of a component already, seams to help when de soldering with my Hakko 808. you just want to add a little bit more mind you, not a big dollop of it.

I'd say setting 1, maybe setting 2 if that does not work. on the heating element trim pot is enough for lead solder. the nozzle on my 808 can be set to some pretty nuts temperatures.. but there not need at all.

When using the de soldering gun, try and get the nozzle centred on the leg of the component and the solder, then very gently jiggle it from side-to-side to make sure the components leg is centred in the nozzle. then give it a second.. maybe two and then pull the trigger while doing a very quick circler motion around the leg of the component with the nozzle. you should now have a clear through whole and leg of the component. if that failed to work, re-solder the components leg and try again.

[X-Col]

The wife bought me the Hakko for Christmas. All 69 caps now desoldered 
Wow, this tool makes things a heck of a lot easier!
Eidis, do you want me to post the parts list for the Ace HD?
I noted down all the parts as I removed them, may be handy for anyone else working on the Ace...

[gypsie]

i recommand to remove and replace caps one by one.

[eidis]

 Hi X-Col !

Congratulations on a job well done ! Almost there. Please have a look at the following article and, if possible, tell me which capacitor values are different for the ACE.

X68000 EXPERT capacitor list
http://gamesx.com/wiki/doku.php?id=x68000:x68000_expert_capacitor_list

Keep the scene alive !
Eidis

[X-Col]

Motherboard (K5709DE) is the same

Daughterboard (K5710DE)
4.7uF (50v): C1, C2, C3, C4, C7, C26, C30, C60
47uF (16v): C8, C22, C27, C35, C42, C52, C53
22uF (16v): C17
1uF (50v): C18, C33, C58
330uF (16v): C9
330uF (6.3v): C10, C12
100uF (16v): C11, C20, C21, C59
100uF (6.3v): C23, C24, C37, C38, C49
100uF (10v): C34, C43, C61
0.47uF (50v): C31, C32, C36, C47, C64
10uF (16v): C25

RGB (K5711DE)
100uF (16v): C16, C17, C19, C24, C29, C30, C31, C32, C35, C37
220uF (16v): C21, C22, C23
100uF (6.3v): C18, C20
470uF (10v): C4, C8, C9
2.2uF (50v): C1, C2, C3

Riser (K5712DE)
47uF (10v): C1, C2
47uF (16v): C3, C4

[X-Col]

Replaced the capacitors on the Daughterboard and RGB, just the Riser and Motherboard to do now.
Waiting for 3 capacitors to arrive to do the Motherboard and Riser.

Nearly there, Fingers crossed 

Update: Motherboard recapped and X68000 reassembled apart from the Riser board (still waiting for 2 new capacitors to arrive). Thought the thing may still work without the Riser attached, but it doesn't. I'll retry once the Riser has been recapped.

[eidis]

 Hi X-Col !

Thank you for the capacitor list and let us know how your project turned out

X68000 ACE capacitor list
http://gamesx.com/wiki/doku.php?id=x68000:x68000_ace_capacitor_list

Keep the scene alive !
Eidis

[X-Col]

Hi Eidis,

No problem :-)

The project, well it went great to start with. After the last capacitors were replaced and the Riser attached it booted and seamed to be working great. Booted with a Human disk fine.
Turned it off and attached a keyboard, booted but went off as soon a a disk was inserted.
So removed the keyboard, booted but still went off when disk was inserted into either drive.
It seamed as though, when the systen drew more power, the screen went blank and system stopped. Now the system tries to turn itself on and off even though the power switch is in the off position (power light flicks between Red and Yellow, and power goes to the fan every time the light is yellow). Turn the front switch on the there is constant power to the fan but the light is Yellow (not green) and the system does not boot anymore).

I suspect the PSU as the system itself seamed to be working fine for about 5 minutes. And as I mentioned in the other thread, there was a screeching sound coming from the PSU. (No screeching sound now though since the problem).

Any ideas which part of the PSU could be causing the switching on and off every couple of seconds? I'm thinking of ditching it and getting a replacement...

[eidis]

 Hi X-Col !

Double check your work and make sure that all capacitors are soldered with correct polarity. Your described symptoms sound like a short circuit protection. Have you replaced capacitors in the PSU as well ?

Update #1: Check the resistors in the PSU. There will be trouble if they are out of spec. First do a visual inspection and see if any of them are burned or broken in half. Next, take a multimeter, and check if their values are not higher than their color band or the schematics suggest. You will most likely need to desolder one end of the resistor to get an accurate measurement. I once had an arcade PSU with the same symptoms - it tried switching on and immediately the protection kicked in and shut it down. It was stuck in an infinite loop. There were three 1/2w resistors which were out of spec. The PSU started working as soon as I replaced them. I even know why it happened. One arcade board had faulty capacitors, some of them even shorted. It drew more power on the +5 line than the PSU could handle and it damaged three resistors.

X68000 Expert PSU Schematics
http://nfggames.com/x68000/Schematics/PSU/X68000_EXPERT_PSU_Schematics_v1.5.pdf

P.S. Don't trash the original PSU, repair it instead. It is very reliable if the capacitors are good and will give you more esthetic pleasure.

Keep the scene alive !
Eidis

[X-Col]

You talked me through the PSU repair Eidi's, it's the first thing I tried. And it worked (apart from that screaching).

I have disconnected the PSU from the system completely and it displays the same symptoms, i.e. Fan coming on and off every few seconds. Just tried it again and the fan now comes on and stays on (PSU not even connected to anything so fan should stay off).
Is there a part of the circuit that controls the on and off in the PSU.?
The voltages the PSU is outputting seams ok, but only output to the molex connector. Nothing from the Daughterboard connector....

Could it be the chips in there causing the issue? i.e. PC31, PC51 & 52? I read somewhere that they can go. As a coincidence, I do have some of these chips upstairs somewhere...

[eidis]

 Hi X-Col !

Is there a part of the circuit that controls the on and off in the PSU.?

I don't know.

Please look at the schematic and tell me which connectors do not receive power. Is +5v line working ?

Keep the scene alive !
Eidis

[X-Col]

When I turn the power on there is immediate power to both 5v (5.06v actual) and the 12v (11.95v) of the molex connector. Nothing else apart from a -10v coming from the grey wire (part of the small connector going to the daughter board with 5 wires)

Just rechecked and there is also a reduced current going to the floppies, 3.3v blue, 1.1v red

[eidis]

 Hi X-Col !

Check every voltage regulator. Especially this:

IC35 (78M05) +5V

Keep the scene alive !
Eidis

[X-Col]

Hi Eidis,

Checked that one, it's marked as IC 31 (78m05) on mine. 1st leg is 8.2v 2nd 0 3rd 5v

D27- 1st 0v 2nd 5v 3rd 0v (fm8-33s)
IC22- 1st 0v 2nd 11.9v 3rd 13.7v (blank but is under ic23)
D23- 1st 0v 2nd 13.7v 3rd 0v (5dl2c2)
IC23- 1st 2.2v 2nd -11.7v 3rd 0v (78m12)
Q1- 1st 3.3v 2nd 120v 3rd 2.2v (k643)
Q31- 1st 3.5v 2nd 123v 3rd 2.3v (C2333)

I'm looking front on so 1st is on left, 2nd is centre and 3rd is right

[eidis]

 Hi X-Col !

Could you please provide part numbers for the mentioned components ?

Keep the scene alive !
Eidis

[X-Col]

Rechecked all red wires and they output a constant 5v
All blue output 11.9v
Updated part numbers as requested

On small connector with 5 wires:
Yellow 0.97v
Orange 5v
Grey -11.8v
Blue as above 11.9v

[eidis]

 Hi X-Col !

The output voltages seem good. Let's try it again. What happens when you connect every cable to where it should go and switch on the PSU ?

Keep the scene alive !
Eidis

[X-Col]

Hi Eidis,

Connected the PSU to the X68000 and just a Red light, the power button on the front of the X68000 has no affect. No power coming from the molex or floppy connectors

After disconnecting from the X68000 and the powering on the PSU, the fan does not spin until it's been on for a minute or so.

Checked a few resistors in the area of Q31 (Transistor C2333) and R36 is actually 471 ohm, the schematic says it should be 221 ohm. May this be causing the problem?

Update: checked the Expert PSU schematic and it is 470 ohm. So looks ok. Got me baffled. Very tempted to just chuck this, been at it since last September 

X-Col

[X-Col]

The PSU disconnected from the X68000 no longer powers up, no spinning fan.
Checked mosfet Q1 (k643) and left pin 1.8v centre 72v right 0v

This contrasts the earlier readings greatly. Any ideas where I should check, something has obviously failed, but what? 

Update: packing it all away for the time being, had enough. May get back to it at some future point, but taking a break from it all for now. Thanks for all your help Eidis. You've been very patient