Hi all! I picked up a nonfunctional ASRock Taichi X570 motherboard that someone threw away. My main goal is it to repair and use it. But even if it's not possible, I'd like to learn about the process.
I'd very much appreciate some guidance.
Here are the steps I've taken to diagnose the board:
When I initially tried to power the system on with the CPU and some memory, it would spin the CPU fan for a fraction of a second before shutting off. No POST code. I tried with two different power supplies that worked in other systems. So its not the power supply. And the CPU is brand new so it can't be that either.
Next step was to take off all the shroud pieces to get a better look at the board. To my surprise, now the CPU fan runs and the board displays the code 00 (fault with the CPU.)
I couldn't see any obviously blown components. So I pulled out an out analogue ohmmeter and started probing capacitors.
There is a cluster of 5 capacitors near the CPU power connectors (seen in image 5.) I measured the resistance between each lead and ground. The negative leads all read 0 ohms and the positive around 12 ohms. The resistance across each of these capacitors is also around 12 ohms. The resistance isn't rising like you'd expect when the capacitor is charging. Is the 0 ohm read indicative of a short on the board?
There is a line of 6 capacitors by the motherboard connector (seen in image 4.) Probing these gave similar results. All the negative leads read 0 ohms. Two of the positive leads read 3 ohms and other four read 12 ohms. This has me confused, because the motherboard can power the lights, CPU fan, and the BIOS chip. Are the capacitors unrelated to the parts of the board receiving power?
Lastly, I probed the 17 capacitors surrounding the CPU (seen in image 2). Again, their negative leads all read 0 ohms. The positive leads read 2 ohms and the resistance across the capacitors also read 2 ohms. As a sanity check, I probed random capacitors around the board. And some of them had reasonable resistances on the negative lead between 10-20 ohms.
I don't know what the next step is. I couldn't find any board schematics. I'm guessing I follow the traces on the board and probe other components.
Where should I be looking now? Any suggestions appreciated.
Thank you.