Sharp X68000 restoration

Shortly after the board, an allegedly working Sharp X68000 arrived, this time a tower model. Hopefully this one will stay working, unlike the desktop one I got a while ago. I also have a 1 MB expansion for this first generation model lying around here too. #RETROGAMING #X68000

(1/3) Decided to open up the X68000 first to clean up a bit. Turned out to already have a 1MB expansion so I didn't need the one I already had, however it was knocked loose during shipping. #RETROGAMING #X68000

(2/3) Of course it had to have battery leakage corrosion. I neutralized it with vinegar and then cleaned up with isopropyl alcohol. Not perfect but better than what it was, until I can dive deep into this thing. Tried taking out PSU but couldn't seemed stuck from behind.

(3/3) Using the VGA adapter I had previously purchased from @edu_arana and my OSSC, I powered it on but alas, it was heartbreak again for me. Second time unlucky with the X68000. We'll see if I can get it to work sometime once I get time to perform some maintenance on it.

Today’s menu a full recap and refurbishment of an OG Sharp X68000. If this piques your interest, follow along for the journey. Let’s try to find out where, this capacitor that was rolling around in the case, fell from. #X68000 #SHARP #RETROGAMING

Starting with the PSU, as is plain to see, there's one bulging capacitor and it's not the only one that's bad. Doused it in white vinegar. The electrolyte has seeped everywhere. Replaced all the caps before moving on to the next step.

Here we can see it running through the ultrasonic cleaner. This is just one of the many baths it took in there. Meanwhile, I measure the capacitors in the PSU just for fun, most of them read like this, so they were dead as a dodo.

Here we can see the lower board being doused in white vinegar, much like all boards were. Trying to neutralize any leaked electrolytic fluid. Then rinsed with IPA and recapped.

Here we have pics of cleaned and recapped RAM expansion board, VSOP board and main board. I put the original oscillator back into the board, hoping that the vinegar, isopropyl and evaporust baths had done anything to it. I also installed an @edu_arana mod to use a CR2032 battery.

Now this gets interesting, seems like something exploded here. What could it be? Remember that loose capacitor?

Yeah, this is where that capacitor came from. Notice one of the PCBs has 4 and the other has 3 capacitors but this isn't the worst thing about that. As you can see in the next 3 pics that capacitor did quite some damage on its way out the door.

I cleaned up the board and patched up the broken trace.

Then I recapped it but this wasn't all that was wrong with the FD drives, oh no.

Somebody had done a number on one of the drives. There was a piece of stuck magnetic disk, a piece of the top part of the spindle mechanism was broken and lodged underneath. Someone went to town on this thing. I tried to undo all of this as much as possible.

I cleaned and lubricated the drives. Also took some time to wash the case, fix the mechanism that allows the handle of the case to pop up and applied some 303 protectant to the shell.

We're now at the final stages, assembling everything and getting ready to see if this made any difference.

Aaaaaaannnndddd... it didn't. Still powers on but does not go into High Reso mode and does not display a picture.

So, after some reading and some waiting, I installed a new oscillator. Also cleaned up the soldering of the components near where the battery leaked. But still nothing.

After some research, I found out that the oscillator isn't exactly a drop-in replacement, you need to snip off one of the pins because the hole where it goes is tied to ground and grounding this pin disables the oscillator. (Thank you @leonkiriliuk for validating this!)

This changed the behaviour of the machine a bit, the LED now flickers and it didn't previously but, still no high reso and still no picture. For now, this is where I stop. To be picked up at a future date.