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I got some new optoisolators. Before installing I tried the PSU again and it had its same symptom of low voltage. I replaced the opto with a new one and it had the same issue. The new opto works okay in the already known-good PSU. Bummer! Since then I've: Applied hot air to warm up the PSU. No...

Not sure if this is documented elsewhere, so here's a map of all the Duo Dock PSU electrolytic capacitors. Everything on the daughter boards is solid-state.

It can be a lot of things. You need to narrow down where the failure is whether it’s the primary or secondary and which rail(s). I recently repaired a PSU which turned out to have a bad optoisolator. It seemed to test fine out of circuit but replacing it did the trick anyway. There are a lot of...

I have a Quadra 840av. Would the rom dump from that help?

You could make an extension but you’d need to use a header which might just break off due to pull stress.

I removed the optoisolator and tested it out of circuit. It seemed fine. Diode check on the LED pins was OK. I attached a 300 Ohm resistor to its anode and bench power supply positive lead. Attached the cathode to the PSU negative lead. measured resistance across the collector and emitter from...

A while back in this thread we talked about how nice it would be to have an Analog Board to MLB extension cable for the 128K/512K. I finally made one today and it works great. I made mine 14" long which gives enough room to move the board around. If I make another, I might do 16" just to have...

My local parts place didn't have a TCDT1100G optocoupler in stock, but did have IL74 which I thought was basically the same (but is not). I dropped it in anyway and the voltages were all higher, but not high enough and the supply would switch on as soon as it was plugged in rather than waiting...

I'm going to journal here the things I've tested so far Capacitors (ESR OK) C04 C09 C10 C11 C12 C13 C15 C17 C19 C24 C30 Diodes D7 (Diode ahead of the -12v voltage regulator) Transistors Q4 TYN682 silicon controlled rectifier (seems OK in circuit, but haven't tested outside yet) Q5 Q6 BUZ80...

@rdmark Very clever! You might want to keep the leads long so you can mount it on the drive frame for easier access.

I have a Duo Dock that works okay with a known good PSU, but it's own PSU isn't working correctly. It has been recapped, but still just gets a faint tick when the power button is pushed. The eject mechanism works okay. 5V for the eject button and ~20V for the eject motor work okay. The power...

The auto inject 1.44MB drives use the same mechanism as this video. Is there a particular step you’re stuck on?

FWIW the symptom you describe is exactly what mine had before recap. Beyond replacing the caps themselves, some nearby ICs were quite crusty. Rather than just clean, I removed them, scrubbed the pads and cleaned up both sides of all of those chips. I know you've ultrasonically cleaned it, but...

She’s all sorted now! I think I’m going to replace my CPU upgraded LCIII with this as my main 68K workstation. Are there any good upgrades for it outside of more RAM?

SDG just posted a good video about tweezers.

One thing not working is boot volume snag keys. CD-ROMs mount when booted to HDD but there’s no attempt to boot to CD when one is chosen as the startup disk, C is held at boot or ⌘+CTRL+⌥+SHIFT+DEL is held at boot. It’s not like it tries and fails. It just immediately boots to HDD regardless...

It’s alive!

I started working on this one today. The power button does trigger the power on circuit and voltages at the MLB PSU connector are all okay. The caps were quite crusty as well as a couple of the serial ICs and U48 which looks like it might deal with reset. I cleaned up all of that. Just need to...

A couple of years ago I bought a $50 pair of hot tweezers from Amazon. They were very difficult to align / keep in alignment and didn’t have good heat control. After upgrading my solder station to a Metcal MX-500, I bought a set of their tweezers. They were about $300 new which is obviously a...