Apple IIGS Maintenance

I ended up with 2 Apple IIGS computers. They were nearly complete. They were dirty, a lot of evidence of mice or more.

I did a basic wipe down of everything to get some of the nasty stuff of of everything before loading them up to bring them home.

On inspection at home, overall I had 2 Apple IIGS computers, with keyboards and the cables but the one keyboard has keys that are stuck and some damage. I also have 3 5.25″ disk drives, a Color Monitor (minus the cable), and a Monochrome Monitor.

I will be making various posts going over the equipment.

The primary thing was to check out the IIGS computers. I needed to see if either was working or reasonable to repair.

I focused on the first IIGS. First I cleaned it a bit better as it was still not very clean. I had checked both IIGS internally for leaking batteries, and thankfully neither battery had leaked, they were dated 1992. On seeing that they were in battery holders I was able to look up that these are the later ROM3 version boards with ROM3 and the additional ram. I removed both batteries, and gave the boards a visual inspection, they looked fine, a bit of dirt and dust.

From there I went to the power supplies. I opened the first one, it is apparently an ASTEC model. The visual inspection of the top looked pretty good overall, although the RIFA cap has some cracking. Nothing scorched or bulging etc otherwise initially.

On removing the PCB from the case to get to the RIFA cap, I found a surprise on the bottom. Under the Large Filter cap (C4), was a leaky black mess. Over toward the nearby C5 there was a mess and the solder mask and solder points looked bad nearby.

I first cleaned up the muck with some IPA while I was preheating my desoldering gun.

I pulled C4 and C5. The large C4 had no marks under it, it didn’t appear to have leaked. C5 though showed evidence of leaking. I take it leaked and migrated across the board, possibly through that large hole or somehow it managed to leak through the board some other way. There is a small pin hole under C4, but there was nothing on the top side, though the hole was plugged up with the gunk. The solder was quite contaminated around a good number of those solder points, and was a bit difficult to remove that old solder from those corroded points. I then had to use the fiberglass brush to remove some of the solder mask where it was damaged and the traces were corroding.

I used my MESR-100 ESR Meter to check C4 and C5. I also checked their capacitance. The large C4 330UF 200V capacitor had the proper Capacitance reading and a good ESR Reading as well. I reinstalled it. With C5, I was surprised to find the capacitance on it was still in spec for a 220UF capacitor, but the ESR was way to high. I’m fairly certain it was where the leakage came from as well, unless it was something that somehow ended up falling into the power supply. I replaced 220UF capacitor with a new one I had in stock. The board isn’t beautiful, but it cleaned up fairly well, everything was superficial. I removed the RIFA, and as I don’t have any spares in stock, I am just going to use it without one to do the testing and get one on order. I removed one of the resistors that had corrosion on the legs, and cleaned it up a bit before soldering it back in.

Above, it how the pcb looked after cleaning up the old solder and resoldering everything. The 3 now vacant holes in the upper left are the holes for the RIFA cap.

I tested the power supply output, and the +5V, -5V, +12V, and -12V all looked good. The +5V was right on, the others had a little variation being a bit low.

The other power supply is a Dyna Corp model. It has 4 RIFAs in it. It also has heat discoloration on the PCB.

I decided I wasn’t going to remove the 4 RIFAs, and that with the state of the PCB (and that I don’t “need” 2 working IIGS computers at this time), that I was going to just close this Power Supply up and not use it.

Now that I had one power supply working, I decided to test both mainboards with it. Since I didn’t know the condition of either monitor and I don’t have the RGB Cable, I used my bench LCD monitor with Composite video. Both mainboards powered up and showed the expected display.

I moved on to one of the Disk Drives. I just picked one of the three drives to do a cleanup and service it. I cleaned the case and cable with Windex and paper towels. I then took it apart. It was a bit awkward to get the drive out of the shell with how the front faceplate locks into the top and bottom halves. I then had to remove the top metal plate, and then the PCB and insulator and other plate below it. From there it was dusty inside, but looked fine otherwise.

I cleaned it internally with qtips and IPA. I cleaned as much of the dust from inside, as well as the rails. I also cleaned the print head with a fresh qtip and 99% IPA. I then put in new Silicone Grease on the rails and worked them a bit to make sure it was distributed well.

Just before putting everything back together, I saw something in the bottom of the drive.

Thankfully I found that and removed it before powering it on. Old gum wrappers some fool stuffed into the drive slot. With one of the drives, I wasn’t able to fully insert a disk into it before loading them up to bring them home, by the time I got home with them, I was able to insert the disk fully. I expect that was this drive, and that had moved out of the way.

I was still testing the IIGS, so I decided to test the Disk Drive before putting it back in the case.

The drive worked properly. I wasn’t making any unexpected sounds, and read the first disk just fine. I had 3 disks, and I tried the other two, and one of them worked. The last disk did not work properly, it would partially read but get to a point that it said to insert the proper disk.

That little Eyoyo monitor does a great job with Composite. It is very forgiving, and I expect when using any of my other monitors on Composite video won’t look as good.

Unfortunately Oregon Trail is not one of the disks, so that means I will have to get solution to let me play it on one of these machines. There are some other programs I would like to try out as well. I have more cleanup to do, the IIGS cases are a mess as well as everything else yet. One of the IIGS cases must be brittle, the lower frame as the one catch that holds the top was already broken when I got it, and then the second one broke when I opened it.

I finished cleaning the Disk Drive’s case and reinstalled it. I also cleaned up the intact keyboard just enough to use it, and it seemed to be working fine. I didn’t test all of the keys.

I found out these will not pass their self diagnostic without a good battery. I need a battery, and replacement for the RIFA cap. I also have to properly clean all the other parts including the IIGS cases.