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Macintosh II error chime
Posted by: Aektann on 2021-07-25 08:14:59
I've got a partially working Macintosh II board. Capacitors are surprisingly goog, however, I get an error chime on start. I tried to press reset/interrupt switches simultaneously and after that, I don't get any chime after startup at all. Could you please help?
Posted by: joshc on 2021-07-25 08:56:04
Error chimes are usually RAM related. These machines can suffer from loose RAM SIMM sockets too. Best to start there I think.

Can you post a high res photo of the logic board please?
Posted by: Juror22 on 2021-07-25 10:18:32
As joshc inferred, start with reseating your RAM, be sure to check the sockets and you may have to clean the ram contacts. People these days don't pay as much attention to electrostatic precautions, but keep those in mind as you are handling the RAM.
Posted by: Aektann on 2021-07-25 12:13:17
Thank you for answering. I’ve got all RAM modules and NuBus cards out and started a motherboard with the boot chime sequence coming again. Then I manages to get a working set of four 256kb SIMMs to boot the machine. The motherboard needs couple of fixes yet It is in great condition and running.
Posted by: Aektann on 2021-07-29 11:04:34
Next trouble: suddenly the motherboard begins to startup immediately after connecting power cord. It looks like starting circuit is always on. What should I pay attention first?
Posted by: zezba9000 on 2021-08-01 13:07:00
Make sure this pin has a good connection. I noticed this was faulty on mine causing issues.
1627848357701.png
Posted by: Aektann on 2021-08-02 01:42:54
Make sure this pin has a good connection. I noticed this was faulty on mine causing issues.
View attachment 33076
Good point, thank you! I'll check it.
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