exxos's Atari, Amiga & retro forum

Certainly looks like with some TLC it is recoverable.

I've seen worse restored, and there doesn't seem to be any battery leakage, so I expect the majority of the corrosion will come off, though you might need to replace a lot of the sockets if they are single wipe and look nasty.

Looking forward to seeing the write up.

The ROM and CPU sockets are turned pin ones. The only other socket I can see is on the replaced chip at the front of the board. I didn’t look closely at that socket.

stephen_usher wrote: 24 Apr 2021 14:53 The ROM and CPU sockets are turned pin ones. The only other socket I can see is on the replaced chip at the front of the board. I didn’t look closely at that socket.

I'm not personally a fan of the turned pin sockets, I find that sometimes contact can be poor, especially if you have chips with legs trimmed where they were previously soldered in.

The corrosion looks worse around the edges, but not terrible. What's the PSU like? Or did it not have one?

It's a bit spotty rusted on the outside but inside it looks clean, just a bulging RIFA smoke generator. There are no fans or really cooling slots in the steel Aztec PSU case so water didn't get in. The frame it sits on is a bit bent, which would have taken quite a force to do as the steel's not thin.

The most important thing is that it looks like none of the weight reached the PCB. The underneath of the PCB is clean with just a couple of bits of dried leaf litter between the PCB and the case bottom.

Oh, and I did get a chance to look at the floppy properly before I left home.

Surprisingly, internally it doesn’t look bad. All the corrosion is on the top of the steel top cover and the front of the aluminium frame but not inside. However, this Sony drive has suffered the same problem as my old Chinon drives from the STs in that the adhesive holding the top head to the finger has failed, so the head has dropped off and is hanging from its wire.

The drive should be serviceable enough for the machine to get through the POST sequence test.

One good thing though was that I found the floppy eject button in the drive! (It’s not attached to the drive itself.)

Cool, sounds like it looks worse than it actually is, hope your trip away goes smoothly and look forward to seeing the repair blog.

I got home this evening and immediately swapped the RIFA 0.1uF X2 smoke generator. I didn't have a 0.01uF X2 in stock, merely a 0.047uF, which was good enough.

I had a hell of a time cleaning the fuse and the fuse compartment but with the help of a file and some sand paper I got continuity there.

So, after a quick test to see that there weren't any bad voltages coming out of the PSU when powered up I put the machine back together as much as necessary to boot up, flick the power switch and...


Wow! It's mostly working!

The display is glitching, looking like a RAM fault but the RAM test is passing. I'm guessing that it may be the video RAM reading stuff which is having issues. The bus arbitration is done using a 256 byte EPROM, which has been replaced in the past and is rather corroded. A bad contact on that chip could be causing video access issues. Still, given what it's been through I'm amazed that it's getting this far!

Well done, what's after that? Fix the floppy?

Wow, considering its overall state, that's quite a win, good job sir.

Here's a video of the boot. The floppy is glitchy too but that's expected.



I'm wondering if the problem is a capacitor as there are a smallish number of electrolytics on the board. I may also try building an RGB to SCART adapter in case it's purely the composite video which is picking up noise from the system.

As for fixing the floppy, I'm not sure it's fixable. I'll probably create a converter board to convert from the Sony cable to a standard Shugart used on a Gotek. This will at least allow me to test things.