IIci clicks on startup | good PSU

[captjon320]

I have had a project IIci for quite some time. I recapped it and ran it through the ultrasonic cleaner; the board looks very clean. When I go to start it, I simply get a click; either from the soft start on the keyboard or the power button. I figured it was a bad PSU, since they seem to go over time. On the shelf it went.

Six months later I have a couple of IIci boards to recap for friends. I compete them and figure that I’ll trouble shoot my project computer. The PSU on my project computer is good, it will boot both the other boards. The other two PSUs are also good and they will boot the other boards. However, all three PSUs only “click” when I put them on my project IIci board.

Therefore the problem lies on the logic board.

I am looking for help, as I don’t know where to start. I have now recapped 11 IIci boards over the years and this is a first.

I started by making sure everything was the correct polarity and had a good connection to the board. It is all good.

If someone can please point me to an area to start troubleshooting, I’d appreciate it!

 

[imactheknife]

I am having the same issue. I have a clean clean iici board, almost mint. It has a massive power issue and I am ready to scream lol. I have replaced the 74hc74, the 74hc132 x 2 and replaced the diodes all around that area. Got it to turn on, get great screen then start to flake out. Now nothing. I have replaced everything again, cleaned pads, checked traces, and still sometimes a sign of life, most times dead. Really getting on my nerves. The start up circuit in your board needs attention.

 

[captjon320]

Thanks for the information, I appreciate it. Where would I find the start up circuit? I apologize about my lack of knowledge in advance.

 

[MJ313]

Never personally raised a IIci from the dead, but here's the diagram:

https://vintageapple.org/gamba2/images/macIIcisch.GIF

 

[captjon320]

Appreciate it, I’ll take a look.

 

[imactheknife]

Sorry, meant to get back to you. Make sure area is clean all around leaky caps / and pads are clean. My board is now complete and working. I have one board that isnt happy, have another iici and a iici logic board coming. The 74hc74, and hc132 ic chips will most likey need removed, and pads cleaned. All my boards have needed it. Also the little black diodes 4 on one side and two on other can be issue too.

 

[imactheknife]

Never personally raised a IIci from the dead, but here's the diagram:

https://vintageapple.org/gamba2/images/macIIcisch.GIF

Lol, lode runner awesome!