So a follow up question for me is -- is there any potential risk to the board when doing a smoke test on a newly recapped PSU? I have a IIci PSU I want to recap, but haven't partly because I wasn't sure how to test the voltages before using it on the board...If you've got a IIsi, you can rig up a test astup with the board out of the case. Running the IIsi or not would be a definitive under load test.
Apply solder to both pads first, heat one pad with your soldering iron, use your other hand to put the capacitor in place while the solder is hot, in effect tacking that side of the cap to the board. Heat the other pad and push down on the cap, tacking the other side.If it works, then I'll need to reevaluate how I can put those new caps on. I probably need to buy a heat gun. :/
Ah, I see. Yeah, and unless it's "no clean" flux you run the risk of causing a short (unless you're liberally cleaning or ultrasonically cleaning the board). And even 'no clean' flux ought to be cleaned off.I'll try a more liberal application of flux. All I have is the thick, brown, sticky stuff. I don't like it because it's hard to clean, but it's all I have.
When I short the pins, the PSU will start/stop at regular intervals as a relay clicks. I assumed that was the overvoltage protection.It doesn’t start up when you press the power key on the keyboard, or when you short the PSU pins to turn it on, or both?
I had to replace a few SMD diodes and ICs in my IIci soft power circuit to get it going.
It sounds like your PSU isn’t connected to the logic board when you short the pins though, is that correct? It should be otherwise I’m not sure what you’re testing. I am pretty sure you need to keep the pins shorted for the PSU to stay on (unlike an ATX). If that works then your PSU is likely fine (probably a good idea to still measure voltages at the connector.) I have a jumper cable that lets me connect the PSU without having it sit on the logic board.When I short the pins, the PSU will start/stop at regular intervals as a relay clicks. I assumed that was the overvoltage protection.
The computer does not turn on via the keyboard except on very rare occasions. That's why I've had the power switch on the rear engaged as I troubleshoot it.