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| IIci keeps turning itself on. |
Posted by: happymacunhappymac on 2022-10-16 11:34:25
This was a really crappy day. I was trying to install MacSD drives (one hardware device, three "drives") in my Mac II and having nothing but trouble. As I tried to fix the problem, I involved more and more pieces of hardware -- a IIci that had some stuff on it I needed, a 7600, and a G4. I more or less broke everything I touched.
I wish I'd stayed in bed.
A couple days ago, I came across a bad adb curly cord. It caused the command key to be stuck down. There was nothing wrong with the kb. Swapping the cable solved the problem. I set the cord aside.
Tonight, I decided I was tired of moving keyboard and mouse between two computers that I wasn't often using simultaneously, and I grabbed the bad curly cord. I should have thrown it away at the first sign of trouble, but I didn't. I used it on the IIci.
Earlier in the day, I was messing around the ci with the lid off, and I dropped a little screw on the motherboard, just north of the simms. I immediately yanked the power cord out, to minimize damage. Then it rolled around a bit as I tried to pick it up. I don't know how much power was left on the board from capacitance in the power supply.
Just about when I was going to go to bed (a couple hours ago), I shut the ci down. And it turned back on. I shut it down again, and it turned itself back on. I disconnected everything, including the scsi ribbon cable and drive power harness. Then I plugged the power cord back in. Sure enough, it turned on a couple seconds later.
I imagine the new problem is due to the potentially-shorted adb cord or the screw.
It looks like I've got a board-level repair ahead of me.
I wonder if anyone has seen anything like this before.
I'd just say screw it and get another motherboard, except this one was recapped last year and I don't want to just toss that $.
Thanks in advance for any clues/advice.
Edit: I also swapped power supplies - put a known good power supply into the IIci that won't stay shut down. That didn't resolve or change the problem. |
Posted by: imactheknife on 2022-10-16 17:13:50
It sounds like a fluke. The psu just started acting up in my iici. I have recapped it too. Just isnt happy to shut down now, just gives me safe to restart. After a few minutes it restarts on its own. I have another good psu, no issues |
Posted by: happymacunhappymac on 2022-10-16 18:28:14
It sounds like a fluke. The psu just started acting up in my iici. I have recapped it too. Just isnt happy to shut down now, just gives me safe to restart. After a few minutes it restarts on its own. I have another good psu, no issues Thanks for the reply. I did swap power supplies and the problem remained with the computer and did not move with the power supply :-( |
Posted by: imactheknife on 2022-10-16 20:44:35
ok, well has the board been recapped? The ADB chip in my experience can affect power on / off. It is right near the power button on back of logic board. Also a 47uf 16cap close as well. The whole power circuit can be an issue, but ADB may be the issue if you used a possible bad cord |
Posted by: happymacunhappymac on 2022-10-16 20:52:12
Hi There,
Yes, the board was professionally (ie not by me 🙂 re-capped last year. Which chip is that, if you don't mind saying? (silk screen legend on board, chip mfr #)
Thanks for the lead! |
Posted by: imactheknife on 2022-10-17 07:54:16
Can you take a picture of your board and post it?
The first pic is adb chip. Second pic is startup circuit. If board was recapped but these chips are still dirty can cause weird power issues |
Posted by: jasa1063 on 2022-10-17 10:28:00
I have had that same issue and for me it turned to be keyboard. Once I swapped it out, I had no more issues. |
Posted by: happymacunhappymac on 2022-10-17 10:35:52
Thanks. In this case, I was able to eliminate that possibility by removing everything but power cord. With nothing attached, it powers itself up. But the keyboard certainly could have been the problem. |
Posted by: happymacunhappymac on 2022-10-17 11:16:32
Here are pictures I took this morning. Thank you. |
Posted by: mikes-macs on 2022-10-17 11:19:40
One of my Mac IIsi does the same exact thing and the (server) button on the PSU is out not in. I assume it’s the PSU on its way out but I really don’t know. The MB has been recapped and works. It simply just doesn’t stay off. I use a power strip switch to kill it. |
Posted by: happymacunhappymac on 2022-10-17 21:15:40
Clarification: This thread isn't intended to gripe about MacSD. After standard learning curve climb, I got it working fine. My flailing wasn't caused by MacSD. I like it because it doesn't freak out and stop working like some of the other SCSI SD drives. |
Posted by: happymacunhappymac on 2022-10-27 11:59:50
Update: Replacing an IC has resolved the problem. |
Posted by: David Cook on 2022-10-27 12:06:27
Update: Replacing an IC has resolved the problem. Wonderful to hear. Which one? |
Posted by: happymacunhappymac on 2022-10-27 12:14:46
I just emailed the fellow who repaired it to find out. I should have waited before posting my message :-\ |
Posted by: happymacunhappymac on 2022-10-27 15:28:12
UE13 is the offending component.
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