troubleshooting bad MB using an identical known good MB

tavr

Junior Member
May 7, 2018
2
0
6
I am looking for some suggestions of things to try in order to diagnose a bad motherboard that gives a beep code error during POST. In particular, if I have an identical working board, can running the two side by side or other types of comparisons help me zero in on the problem?

Some details: These are laptop MB's with soldered CPU/GPU. The bad board's error code is six beeps a few seconds after turning on the machine, and this is an AMI bios. At least, I think it is six beeps...they come in two groups of 3 each. I inspected the bad board by sight, and there is no visible damage to any of the components. I also tested most capacitors for a short circuit thinking that this might be an issue, but did not find any. The only way to have something different happen is to take out all the RAM; in that case, there is a single long beep.

Any suggestions would be appreciated.
 

Ratman6161

Senior member
Mar 21, 2008
616
75
91
Brand and model of laptop? What CPU?

Hint google it. For example my motherboard is an ASROCK AB350 Pro4. So if I google "ASRock AB350 Pro4 BIOS Beep Codes" I get a full list.
 

tavr

Junior Member
May 7, 2018
2
0
6
This is a general question, brand doesn't matter. Schematic for this board is not publicly available, so the known-good board is the best information I have. I ultimately stumbled on this class in which the lady describes some pretty good techniques for locating the trouble spots on boards using an identical known good board: https://www.youtube.com/watch?v=TOYIu7UwTqI Hopefully someone else finds this helpful.

Btw, the issue in my case turned out to be not hardware-related, but software: the BIOS chip was badly flashed.