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I managed to power the board up and got this screen. Any thoughts what the issue could be? No startup sounds at all. The analog board is known working and was fully recapped. The Mac works without the accelerator.

They both are 10uF/16V, just different sizes. Thanks for checking the picture nonetheless. Here's another picture of them:

And which open sourced application would deliver the biggest value to the Apple retro computing community?

I'm looking for the manual and any installation guidance for this Accelerator. The board replaced the 68000 CPU and was soldered directly onto the logic board. It came with a separate power supply:

My 512k had the same issue and reflowing of these pins helped to fix it.

I've recapped a IIfx PSU. It turns on as expected, though the resistors R26 and R15 of the PSU get very warm. After a couple of minutes (less than five), R15 is already at 131.7C (269F). What could be the issue with them? Or is this normal? I suppose such a high temperature is not desired...

I managed to break off a part of the "floppy disk in drive"-sensor part in the 400k drive. Does anyone have a STL file so I could 3D-print it?

I see - and sorry for the typo. I meant to write "out" not "not" :-). The Colour Classic I worked on underwent a full recap. I can highly recommend doing it for yours too. It'll have to happen anyway so why not do it now?

Just not of curiosity: How did you measure each capacitor? Did you desolder each of them?

Another update: The CRT went dark again. I investigated further and reflowwed all connectors. This must have solved the issue more reliably. The Mac runs now reliably.

Update: The 512k Mac screen stopped working shortly after I had put it together again. I then decided to replace the BU406 with a new one and voilà, it's working again.

It works again. After putting the transistor back in Q3/2, refloweing the J4 joints and one of W6 that looked odd, the CRT is back to live. Thanks all for sharing your thoughts!

I recapped the analog board of a Mac 512. All worked fine. After it was stored for a couple of months, I started the Mac again But this time, the CRT would not turn on. There was a solid boot chime/beep though. Voltage on the 5V and 12V/-12V rails were normal. Troubleshooting done so far: -...

This may be a another trivial one: Did you try to turn it on with a different keyboard and ADB cable?

thanks, that was very helpful.

Yeah, these had minor corrosion, thanks for pointing them out. But they were not yet broken. Any other ideas how to resolve the power issue?

This IIcx loops from on to off as soon as a known working (and recapped) PSU is connected to mains. The loop cycle goes a brief moment in "on" mode, then to off, then on again, etc.. No peripherals were connected to the board while powered on. What I have done so far: - Recapped logic board...

Thanks, it was UE13 in my case. Chip was replaced and the IIci powers up normally.

@gagigu Does your Classic II still need a recap? I would still have capacity in June and live near Zurich. PM me if needed.

I checked continuity of the switch's pins. Switch off position: Continuity from pins 1A to 2A & 1B to 2B Switch on position: Continuity from pins 2A to 3A & 2B to 3B Does this make sense?