Recent content by SpocksBeer

Welp I'd be suspecting the transistors either side of that arrangement, marked 5 and 7 in that schematic. One or both might be damaged and switching to ground when it should not.

Think that's indicative of CPU not executing code. Try reseating the ROMs?

Ah, the four most difficult to maintain Compacts. Good luck! There's an Aussie Vintage Apple group on faceache worth joining

It does that much without UA5 being present? Interesting I would not have expected that. The variation in screen brightness may be down to electrolyte that has seeped into the PCB of the analogue board. It's quite porous and a real pain to deal with. Usually a deep soaking clean is required...

I'm no expert, but I guess you could try injecting 5v to the pad for pin 6 of UA5 (or pin 37 of UB5). I think this would simulate reset going high, allowing the CPU to do its thing.

Unfortunately no, the sound chip is integral to the reset circuit and the CPU will not boot without it. Edit to add, yes flux is always a good idea at any stage of soldering. Part of the problem is getting heat into the corroded solder and not into the surrounds (like the pads). Flux will...

It's kind of hard to tell. There seems to be a lot of black goo left on pads, but yeah, that UA5 area looks pretty bad. Soak with IPA (the cleaning fluid, not the beer) and clean well, but gently. Scrape the pads, very gently, with something sharp to get the goop off, if indeed the pads are...

Yep, 2 for 2. Second SE/30 chassis also had a flyback with surface corona discharge visible. Cleaned this one up too and it went away, solving the noise issue. This one was also exhibiting a full screen rhythmic rolling effect (the original issue in the first post was far more random). It...

Ruled out the logic board again by taking the SE LB and putting it in the SE/30 chassis (result: video noise), and taking the "noisy" logic board and putting it in the SE chassis (result: rock solid video output). then I looked at the flyback while it was running. Oh. Well, there's your...

Cold starting it tonight showed the issue still there, perhaps a little better, perhaps not. I have two complete SE30 units, and now that I'm looking, both are showing the problem to varying degrees. :( In both, the analogue boards are already recapped. The SE ABs seem to be better built than...

Well, OK, I'm back on-board with it being an analogue board problem. I reflowed the yoke pins again, but it made no difference. So I swapped the logic boards over again, confident that the problem would follow it, but nope the "clean" LB did the same, but worse. This time there was a lot of...

Ok, I'll spend a little more time swapping boards and reflowing things. I could have sworn I reflowed the yolk on this one already, but perhaps not. I've only got two of the mid-gen (I guess?) SE/30 LBs, so no factory bodge wire but socketed CPU, to test with. Could try my SE board too I...

Wondering if anyone has encountered this before. My SE/30 exhibits some subtle analogue video noise on cold boot, which seems to clear up shortly after its reached the desktop, or at least reduce to the point of rarely being noticeable. It's a rolling distortion that seems exacerbated by or...

Looks to be 9mm of spring, or 15mm including both hooks. I'm sure there's more technical terms for both those things. Diameter looks to be somewhere around 2.5 to 3mm You should have a crack at making your own, plenty of good guides like this one.

Chip quik