X68000 Compact XVI + X68030 Compact Repair / Restoration

Started by BlueBMW, June 04, 2012, 04:58:37 AM

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X68000 Compact Repair / Restoration information

Typical System Issues:

- Unit does not power on
- Unit does not power on completely (one or both floppy drives do not power on)
- No, Low or distorted Audio
- Software fails to load reliably.
- Floppy drives shut off randomly while system is on

Typical Failure Points:

- Power supply capacitor leakage / failure
- Mainboard capacitor leakage / failure
- Floppy drive failure
- Floppy drive capacitor leakage / failure

Repair / Restoration

Part 1: Disassembly

Disassembling the Compact units can be an exercise in frustration.  There are basically a few screws to remove and the rest is all snaps and clips.  The screws are the easy part, the clips are what make it difficult.  The key is to go slow and not force anything apart.  Use the lightest force when possible

<I'll be taking some pictures to add to this section>

Steps to disassembly:

- Remove screw from base stand and slide base off.
- Remove rear expansion port covers and any caps on any connections.
- Remove side panels, front bezel, rear bezel and top bezel
--- Go slow and careful with these pieces, they all kind of slide / snap together so go easy with them such as to not break them
- Remove outer RF shielding
- Remove floppy drives (use caution in removing the ribbon cable connections to the drives)
- Remove rear floppy / hard drive interface board (also use caution with these ribbon cables)
- Remove front controller port / volume knob board (again, careful with the ribbon!)
- Disconnect power supply connector from mainboard and remove the complete power supply unit
- Flip the unit over and carefully unsnap the mainboard from the plastic case.
- Carefully remove the five ribbon cables from the mainboard.

Now that the unit is in pieces, its time to repair / restore each part

Part 2: The Power Supply

While the power supply in the Compact units doesnt seem quite as failure prone as the tetris block units, they do need attention at this point.  At this age, you will likely have several capacitors starting to leak.  This leakage can short out components of the power supply board and eventually cause major failure resulting in a lot more problems than just the capacitors.


Disassembling the power supply is fairly straight forward. 

- Remove all externally visible screws (4 total)
- Remove cover with holes in it.
- Remove clips that clamp components to the main shell
- Remove the two screws that hold the boards to the shell
- Remove PCBs from shell

To service the capacitors, I find its a LOT easier to do if you separate the two boards from one another.  Apply some flux and use some desoldering braid (or a pump) and desolder the two sets of connections that hold the two boards together.  Once apart you can change capacitors and clean the boards a lot easier.

Capacitor replacement:

I recommend you replace all the electrolytic caps on the power supply board.   I also recommend that once you remove all the old caps that you then clean the board to remove all leaked electrolytic solution.  You can use soap and water (do not immerse!) but make certain you completely dry the board before use.   Canned air is good for drying out underneath components.

Here is a chart showing the sizes, locations and polarity of the electrolytic capacitors (Black side is ground) Credit goes to Red Ghost (on the pcenginefx.com forums) for the chart style.

Here is a list of the capacitors, their sizes and C numbers:

C11 200v 1uf
c62 50v 3.3uf
c60 25v 47uf
c54 35v 82uf
c57 35v 82uf
c22 25v 100uf
c59 25v 100uf
c58 25v 100uf
c55 25v 100uf
c53 10v 1800uf
c51 10v 5600uf
c52 10v 5600uf
c6  200v 270uf

Reassemble your power supply and set it aside!

Part 3: The mainboard

Like many other electronics of this time period, the SMT electrolytics have a bad tendency to leak and damage the mainboard.  This can cause a myriad of problems.

Replace all of them and be sure to clean the board thoroughly to remove any traces of electrolytic fluid.

Below is a chart detailing the location, size, and polarity of the electrolytic capacitors on the Compact's mainboard, controller board, and expansion board:

It would also be a good idea at this time to change out the SRAM backup battery.

And here's a list of the capacitor numbers, voltages and ratings:

C1SUB 50v 0.47uf
c1 50v 1uf
c2 25v 4.7uf
c3 6.3v 470uf
c4 6.3v 470uf
c5 6.3v 470uf
c6 6.3v 100uf
c7 6.3v 47uf
c8 50v 0.47uf
c9 50v 0.47uf
c10 50v 0.47uf
c11 25v 4.7uf
c15 6.3v 47uf
c16 6.3v 470uf
c18 6.3v 100uf
c19 6.3v 100uf
c20 6.3v 100uf
c21 6.3v 100uf
c22 6.3v 100uf
c23 6.3v 47uf
c24 6.3v 47uf
c25 50v 1uf
c26 6.3v 100uf
c27 16v 10uf
c28 6.3v 100uf
c29 25v 4.7uf
c30 6.3v 470uf
c31 25v 4.7uf
c33 50v 0.47uf
c34 16v 100uf
c35 16v 100uf
C36 6.3v 100uf
c37 6.3v 100uf
c39 25v 4.7uf
c40 25v 4.7uf
c41 25v 4.7uf
c42 6.3v 100uf
c43 6.3v 22uf
c44 6.3v 100uf
c45 16v 100uf
c46 6.3v 100uf
c47 6.3v 100uf
c48 50v 1uf
c49 6.3v 100uf
c90 6.3v 47uf
c348 50v 1uf
c351 50v 1uf

Controller port board:
c501 6.3V 100uf

Expansion board:
c701 6.3v 47uf
c702 16v 47uf
c703 16v 47uf

Part 4: The floppy drives

I havent seen too many compact floppy drives fail, but I have had some behave erratically.  Specifically I had a pair that would work fine 80% of the time, but would shut off at random while the system was running.  I changed the capacitors in them and the problem went away.

Disassembling the Floppy Drives:

- Remove the drives from the system being careful not to damage the two ribbon cables that connect them.
- Remove mounting brackets from the drives

- Remove metal housing

- Disconnect head motor ribbon cable bottom side
- Disconnect eject button/LED connection
- Disconnect large wide ribbon cable
- Disconnect two connectors for eject mechanism motor
- VERY CAREFULLY disconnect the twin ribbon cable that connects to the drive heads.

-Remove mainboard from floppy drive

- Replace 4 capacitors on FDD mainboard
- Lubricate eject mechanism and read head drive
- Reassemble

Here is a capacitor chart for the FDDs:

Part 5: Reassembly

- Re-mount the mainboard into the shell and reattach the plastic shield sheet to the bottom.
- Re-attach the expansion slot board to the mainboard and snap into the shell
- Re-install the external floppy / hdd board into the shell and connect the two ribbon cables
- Re-install the floppy drives and attach their two ribbon cables
- Re-install the front controller / keyboard port board
- Re-install the power supply
- Re-connect the internal speaker
- Re-install the metal shielding around the unit
- Re-install the plastic housing carefully, then attach the bottom base

Test the system.  If all went well you should have a fully functional compact unit again!

X68030 Compact Repair / Restoration information

The X68030 Compact is very similar to the regular Compact.  There are fewer capacitors to replace and the power supply is the same.  Repair / restoration of these units is basically the same as the regular compacts.

As I find more information to add to this thread, I'll update it.  Also I'll be taking some more pictures for some of the assembly/disassembly steps and adding them later



this should be stickied!!! Beamer you are awesome!


No real need for sticky since if anything I post is worth a bit, someone will add it to the wiki.


Quote from: BlueBMW on June 04, 2012, 04:58:37 AM

Part 4: The floppy drives

I havent dealt with any non functional 3.5" drives yet, so I havent attempted to disassemble one yet.  I can see at least one radial capacitor that should be replaced in them though.  I'll update this when I have more info on the floppy drives.

about the 3.5" floppy drivers, I'd like to comment that on the main board there are 3 capacitors of 10uF 10V and 1 capacitor of 47uF 6.3V.
In my case all of them, on both units, had a massive leakage.
Since those capacitors are located in parallel to the main power lines, in order to suppress spikes while the motors are operating, I do kindly suggest to replace with ceramic ones (low ESR, tiny size 2012/0805, X5R or X7R, 10V, of course not polarized).
Meanwhile WD40 will help to make the mechanism smoothly moving as well.


Quote from: kinmami on June 07, 2012, 10:09:52 PM
about the 3.5" floppy drivers, I'd like to comment that on the main board there are 3 capacitors of 10uF 10V and 1 capacitor of 47uF 6.3V.
In my case all of them, on both units, had a massive leakage.
Since those capacitors are located in parallel to the main power lines, in order to suppress spikes while the motors are operating, I do kindly suggest to replace with ceramic ones (low ESR, tiny size 2012/0805, X5R or X7R, 10V, of course not polarized).
Meanwhile WD40 will help to make the mechanism smoothly moving as well.

Ahh good info.  Ill take these floppies apart and make some charts / notes on them.


Updated with more details about floppy drive restoration.


Hi BlueBMW,
I found your guide very helpful, thanks for it.But now  I have a small problem, where to put this piece?

I presume it comes from the base:


but I can't understand where exactly.


Hmm.... I dont recognize that piece.  But the next compact I disassemble I'll look for it and let you know!


Ok, thanks.As  I said I'm pretty sure that this piece  comes from the base since I not only slid off this but also disassembled it.


I've never encountered that in my Compact either.  It looks like a cellphone antenna tool.  Seems designed to go around something, a wire or spring or other moving/sliding part?


Updated the original post with information on the X68030 compact


Incidentally, is the CPU socketed or soldered on the 030 Compact? What about the oscillator?

I've never been able to figure out whether it's possible to swap the 030/25 on the 030 machines for a faster one.


The 68030 is socketed but Im not sure about the oscillator.


Thanks BlueBMW, I'll take a look on these instructions next winter when I take my Red Zone apart.

- Saku


During deassembly of my compact floppy drives I discovered that each unit has a surprise secret extra capacitor not mentioned in the charts.

It is on the board below the top one that you remove to get to the 4 already mentioned. I have no idea how to get to it as it would require quite a bit more deassembly. It looks like another 10uf 10v like the three on the top board, but cannot be sure.

Unlike the top three that could easily be replaced by tiny Tantalum SMD caps the surprise one actually has one of its legs goint into a hole, and finding 3mm canned caps is hard.

Once I can be arsed, and have found a suitable replacement part, I'll try to diassemble a drive and see about swapping it.

Until the I would appreciate some input to my problems in this thread:



Behold, the secret capacitor:

The markings on it are as follows: 55 R on one side and 10v 10 10v 10 on a column on the other side. Although it is the same size as the 10uf 10v caps on the top board it seems to have different marking which is strange. I think it is 10uf 10v as well though. If you are doing a recap better catch that one as well for posterity.


Hi, some time ago I noticed that hidden capacitor, me too but  I never been  able to reach it.But, how did you get to reach this?It seems you have to disassemble the motor spindle cover.


Oh, getting to it is actually a lot easier than it looks. The metal frame that is left once you take off the top board actually has a separate top and bottom part to it. You can force the top part off if you try to pry it off from the bottom frame at the front. There are three places on each side where the top and bottom fit together via these round pegs.

You will need a bit of force applied to the right place to pry one of the pegs out of its place at the front left or right, then the one on the other side and the assembly should just pop out.

You can then change the capacitor at leisure since it is in full view. Since I didn't want to deassemble the floppy further I just clipped off the old cap leaving all of the one through hole leg behind. Then I just soldered the new cap to that leg on one side and the solder pad on the other.

Replacing that lone cap is highly recommended though. Its function seems to be related to rotating the disk as one of my drives were not spinning until I replaced that cap. If you top caps need changing then there is a good chance that the bottom one needs servicing as well.

Sadly both my floppies are still really finicky.

Floppy 0 can boot games but out of the 10 new floppies I have it only wants to read from the 3.

Floppy 1 fares worse still as it fails to read even those 3 all the way through. I can never get it to fully load a game, it usually results in read error halfway or so through.

This sounds crazy but I think neither floppy was reading anything while my compact was standing up. I had to lie it down for them to work, but that might have just been a coincidence.

I've already cleaned the heads, but I think I may need to do that again. After that I am at a loss as to what to do.

I used tantalum capacitors for the top board of the floppies. You guys think that might be causing problems or is it the read heads that needs to be realigned?

Oh yeah. I took off my PSU fan and now I do not know which way it was facing. Is the fan supposed to blow air out of the PSU or into it? Could someone put a hand on their compact fan and tell which way the airflow is going?


Well, looks like floppy drive 1 is fried.

I am not sure what happened. After cleaning the heads I reconnected both and during testing I suddenly noticed that the floppy light was growing dim and the eject mechanism was growing very sluggish. When I smelled a burning smell I quickly turned off the compact.

The smell was coming strongest from the backside of the drive but I could not see anything that looked burned. As a precaution I changed all of the tantalum caps with electrolytic ones. Unfortunately the only signs of life remains the disk spinning when I start up the compact. The head does not move, the led does not turn on at all at any time and pushing eject does nothing.


Well, I have done some repair tries some year ago on CompactXVI FDDs but I gave up, they are very fragile and not well-engineered IMHO.At the last, I build a cable to use external generic 3.5" and 5.25" FDD , they works but obviously I cannot use special function (soft-eject, LED blink, etc..) and they require a software driver (EXPFD.X) in order to proper function and a SRAM driver (s_expfd.r) in order to boot from them.
Regarding heads aligning we could connect them to a pc with a special cable (a pain in the a.. sinec Compact use FFC cables and not regular ribbon ones so we need also an adapter) and then use some alignement software as done by 'doublefash' user, check this thread about:



I'll try to swap the top board between the working and none functioning floppy drive to see if it changes anything. At the very least it would help me to see whether the problem is with the top board or not.

The floppy drives are of real simple make though. I wonder whether they are more or less robust than the average floppy drive found in older PC's. It seems that for certain components the X68000 floppy drives uses stock parts. the top and bottom board also seem to be very simple and have few parts which should be easily replaceable upon failure.

My pappy is a technician who has been repairing electronics since the 70's. If I cannot figure it out myself I can always turn to him.

Of course if I get a CF setup going all that becomes irrelevant.


If you figure out a consistent method to repair compact drives Ive got 14 broken drives that Id love to see fixed someday.


Indeed, I wish there was such a thing. Unfortunately all my board swapping netted me was two useless drives instead of one useless and one semi-functioning drive.

I found put that the problem seemingly is with the top board, though what exactly I cannot tell. However when I swapped the boards back I found out that my working drive would no longer read disks where as before I could consistently read some.

Maybe this is a over voltage issue where the defective top board somehow managed to disable some parts of the good drive during the swap.

It will be a few months before I can get my pappy to have look at the drives, so a solution is not forthcoming.

In the meantime, since I have nothing to lose I'll be trying to take my floppies completely apart, even the bottom board so I can have a look at its underside.

I'll report back if I find anything.


I suppose at some point I need to bear down and try and figure out repair on these drives too.  I know they can be interfaced with a dos PC and head alignment tools exist.  Just a matter of figuring it out.  I know one guy who's really good with electronics, I might just have to send him a compact with these drives and have him figure out how to repair them.


Before that I would make sure to do a simple recap of each malfunctioning drive. That includes the secret fourth capacitor on the bottom board. That one seems to play a vital role in rotating disks so it is important.


Just a silly question. That secret capacitor wouldn't happen to be a bipolar one ? If so, and if you replaced it with an ordinary one, that would explain the magic smoke.

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


I doubt it. I swapped the secret cap with polarized replacements in both my drives, but only the one malfunctioned, and then a long while afterwards.

Furthermore the problem seems to be related to the top board, not the bottom one, and in the hopelessly broken drive the disk still spins.

I still have the caps I replaced around. I can go home and have a look at them. If they are not polarized then they should have no marking on the negative part like on other capacitors, that will settle it for sure.

Anyhow, I tried to take apart the bottom part of the broken drive and made a mess of things.

You see, the bottom board is connected to the frame by way of a thin, fragile little ribbon cable and I managed to sever it.

In short I would not recommend taking the bottom portion of the floppy drives apart.


For posterity I should mention that after looking at the secret caps I dug out of the compact floppies they were indeed polarized.

Oh, and by the way, both legs of said cap go into holes on the PCB. The solder was placed such that it seemed like one was a solder pad and the other a hole, but they are both holes.

So find some tiny 10uF >= 10V caps and get those illusive bastards changed.

Last but not least, while googling around I found a site that I wish I knew of before I started dissembling my compact with all the finesse of a blind chimpanzee.


Someone more industrious than me should translate the more poignant bits and stick them in the wiki accompanied by those wonderful step by step pictures.


today I spent some minutes try to figuring out how to separate the two metallic parts in order to reach that hidden cap but without success.I noticed that metal is quite ductile and malleable and and if you leverage on it tends to deform.


Yeah, the metal parts bend easy, but they also bend back easy.

Anyway, the trick to opening one is really easy, you just have to pry the two front pegs out of their place, then the top part just pops out.

I seem to have forgot how I got the bottom part off, but that one is a lot more challenging and luckily not needed for replacing the bottom cap.


OK, looking at the picture above, could you indicate these round pegs?


The approximate location of the pegs are circled in red. As you can see the middle pegs are plainly visible and have no roof over them. The front and back pegs slide in a rail. What you will have to do with the front legs is pry them out of their rail then you are set.

Put a flat head screwdriver in the space at the pry points and wedge those pegs out.



Can't find  10V 10UF electrolytic caps on the net (for the FFD)????

Do you know which model i can use to replace them ?

Question : can i use 16V 10UF instead ?



Quote from: gypsie on October 10, 2013, 05:45:23 PM
Question : can i use 16V 10UF instead ?
You can. Anything that is 10uF and >= 10v for those one.


Quote from: lydux on October 10, 2013, 07:52:03 PM
Quote from: gypsie on October 10, 2013, 05:45:23 PM
Question : can i use 16V 10UF instead ?
You can. Anything that is 10uF and >= 10v for those one.

Ok i will use 10uf 16V. I hope the size is not too big ...


A word of warning. They have to be super thin to fit inside the compact drive. I would recommend you go with tanthalum or creamic caps over electrolytic since those two types are usually much slimmer.

I for one had a deuce of a time finding electrolytic caps that would fit.


Yes i think that electrolytic caps are too big. I will try to find ceramic or tenta caps.


I think this thread should be stickied.
Is that a good idea?


Hoping someone here might have the pictures for the cap locations in the original post.

I have a Compact that came in with several seemingly missing caps.

Not mentioned here, but I'm also in need of the value of the only capacitor on the SCSI PCB.