X68000 repair thread

[famiac]

Model: Expert HD

No blinking floppy lights

It receives a red light when plugged in and nothing else happens

[BlueBMW]

Best place to start would be rebuilding the power supply.

Replace all the capacitors and also the following components:

Part numbers next to each are from Mouser.com

ZD51: 15V 0.5W zener diode:  78-1N5245B
ZD32: 4.3V 0.5W zener diode: 610-1N749A
ZD31: 6.8V 0.5W zener diode: 512-BZX79C6V8
Q31: 2SC2333NPN Transistor:  512-KSC2333YTU
Q32, Q33, Q53: 2SC1815Y Transistor: http://www.ebay.com/itm/500pcs-2SC1815-2SC1815Y-C1815-NPN-50V-150ma-Toshiba-/270982641179

Make sure to wash the board really good before installing the new parts.

[famiac]

It has a new power supply... I need to open it first. Anybody know the safest way to open this machine? I don't want to damage it any further.

[BlueBMW]

So someone has changed it out with an ATX power supply?

To open it, there are three screws on the back per side panel.  The panels slide back and then out, but there are clips that snap to the front panels and they are sometimes stubborn to break free.  sometimes you have to just work them a bit.

[famiac]

Above is what the seller claimed ^

This thing is a freaking mess



Doesn't look like there's an atx psu... The bastard

[SuperDeadite]

Looks like lukemorse's handiwork.  Hope you got a really good deal on that piece of shit.  You are most likely better off buying a new machine and using that one for parts unless you have a LOT of free time on your hands.

[famiac]

Are you kidding me... Goddamn. I paid 110 bucks for it a year ago

[SuperDeadite]

Can't be certain, but it's common knowledge he sold a few systems and shipped them with an old Apple Macintosh monitor adapter.  These are completely incompatible, the the buyers all fried their video boards.  Probably your seller was one of those buyers, tried to fix it, and dumped in online for sale out of frustration.  And yes this was about a year or two ago when this happened, so the timing fits too, and the machines were Expert HDs if I recall correctly.  That probably is an ATX PSU, just had the case removed so it would fit better.   Though that is one shitty install job.  Why the hell would you solder directly like that?

Anyway a real pro like lydux might be able to help you here, but man that looks terrible.  Still, at only $110, it's worth it for a spare set of drives, assuming they still work.

[BlueBMW]

I was going to say $110 is quite cheap...

Be VERY careful with that thing... an exposed power supply like that can shock the shit out of you!  Is any of the stock power supply housing still intact?

If you want to make a go of things... Id replace that power supply first.  There aee some small ITX units that fit eell, or I know some people have used an external power supply.

[lydux]

Wow !! What the hell is that ?!!
Stop powering it up ! This thing is really dangerous in this state...

We can't deduced the state of the whole machine right now, I just hope the guy who made this hasn't done mistakes in the wiring (like inverting the +12v and +5v).

Well, we need more pictures actually :
- Is that burning traces I see in the upper left corner ?
- A good quality pictures of the main and IO boards might be usefull.
- And an important one considering is has fried an LCD monitor : a picture from the video board (the small block with the DB15 output connector). We generally see a blown transistor in it, and in which case is possible to be the only one really dead part.


As BlueBMW said, if you want to try fixing it, the first thing to do is to throw away this PSU, and this strange bare pcb behind the floppy drives. Just keep the cables that plug within the main board, io board and floppy drives.


Consider it will be an hard job... How is your electronic skills ?

[famiac]

Wow !! What the hell is that ?!!
Stop powering it up ! This thing is really dangerous in this state...

We can't deduced the state of the whole machine right now, I just hope the guy who made this hasn't done mistakes in the wiring (like inverting the +12v and +5v).

Well, we need more pictures actually :
- Is that burning traces I see in the upper left corner ?
- A good quality pictures of the main and IO boards might be usefull.
- And an important one considering is has fried an LCD monitor : a picture from the video board (the small block with the DB15 output connector). We generally see a blown transistor in it, and in which case is possible to be the only one really dead part.


As BlueBMW said, if you want to try fixing it, the first thing to do is to throw away this PSU, and this strange bare pcb behind the floppy drives. Just keep the cables that plug within the main board, io board and floppy drives.


Consider it will be an hard job... How is your electronic skills ?

I only tried to power it up once, then i unplugged it and opened it up.

I will take pictures of all the boards for you.

What is the safest way to remove the psu? I don't want to risk electric shock.

I'm very good with a soldering iron.

I've done repairs and mods for tons of other systems. But never on a computer like this. Currently working on this and a famicom rgb mod

I was going to say $110 is quite cheap...

Be VERY careful with that thing... an exposed power supply like that can shock the shit out of you!  Is any of the stock power supply housing still intact?

If you want to make a go of things... Id replace that power supply first.  There aee some small ITX units that fit eell, or I know some people have used an external power supply.

Where can i find the stock power supply housing?

[BlueBMW]

Its going to be hard to find another stock power supply housing, but as lydux said, keep all the wires / connectors that go to the floppy drives, mainboard etc.  You will need them if you do a power supply swap.

Ive used these before and they seem to work and fit ok.

http://www.ebay.com/itm/APEVIA-ITX-AP250W-250W-Mini-ITX-Power-Supply-/300942177589

[famiac]

PSU removed

[caius]

PSU removed

Good and now, please, throw it into the trashcan before it kills someone...

[ApolloBoy]

Certainly looks like the handiwork of someone who would misspell "through" as "threw".

[famiac]

Ok... Now what?

[BlueBMW]

Get a replacement power supply like the one I linked above and prepare / install it as per this guide...

http://nfggames.com/nfg/x68repair/

Once youve got the unit powering on properly we can help you asses if there is any other damage that needs to be repaired.

[cr4zymanz0r]

Oh hey, this sounds just like my first X68000 endeavor. It probably shorted and delivered a large voltage over ground which then came to fruition when the previous owner plugged it into the monitor. I bet if you open the other side and take out the video board there's probably a component on it that's exploded (that's part of what happened to me). After the PSU issue in mine was fixed I could get to the loading music on some games (which would then lock up a little bit later), but I never got video even after replacing the exploded transistor on the video board.

I'm handy with general electronic repairs, but I don't have a lot of X68000 expertise so I ended up just keeping the working floppy drives and working out a trade to get a working X68000 that had no working floppy drives. Best of luck to you.

[famiac]

So maybe i should just keep it for parts instead of spending more money on a psu on the basis that MAYBE it will work...

Now... Where to find a broken x68k...

[BlueBMW]

They're usually all over yahoo japan auctions, but by the time you buy one, pay a proxy service and ship it, you'll be well over the $110 you spent on your current system.