Hi all! I'm a newbie to to the forum and electronics repair in general.
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:
I first tried powering the board without a CPU or memory. The lights turned on. As you'd expect, the board wouldn't boot.
Hoping the board worked, I bought a compatible CPU on amazon. I wanted to buy it new so that I can return the CPU if the board is irreparable. This gives me a time limit of about a month to test with a CPU. I chose the Ryzen 7 5700G, which is on the supported CPUs list.
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, the board could make more progress now. Was a metal shroud bit shorting something out??? Now the board can keep the CPU fan running and displays the POST code 00 (fault with the CPU.) The board has an 8pin + 4pin connector for the CPU while both my PSUs only have an 8pin (one is split into two 4pin connectors). I read that the board should boot fine with only an 8pin connector, and that you can even try powering it with just the 4pin connector. I tried all combinations of plugging in a 4pin connector and got the same result. I also tried both PSUs to double check.
Then we move onto inspecting the board for damage. Here are some pictures. The compression made the images pretty blurry. I can upload closer shots of any specific area.
I couldn't see any obviously blown components. So I pulled out an out analogue ohmmeter and started probing capacitors. I hope I'm using it right, please let me know. Each time I change the resistance range, I touch the leads together and use the adjuster knob to set the resistance to 0. Then I plug the black lead into COM and keep that on the I/O shield. I plug the red lead into OHM and touch that to the capacitor legs on the back of the board. When measuring, I start at the lowest resistance range and work my way up until I get a read.
There is a cluster of 5 capacitors near the CPU power connectors (seen in image 3.) 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 (touching COM to the negative lead). 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 5.) 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. Is 0 ohms on the negative lead of a capacitor normal? Am I measuring it wrong? Or 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 also probe MOSFETs and buck converters. If I need to replace components, I have access to a hot air station and soldering tools through school.
Where should I be looking now? Any suggestions appreciated. Thank you.
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:
I first tried powering the board without a CPU or memory. The lights turned on. As you'd expect, the board wouldn't boot.
Hoping the board worked, I bought a compatible CPU on amazon. I wanted to buy it new so that I can return the CPU if the board is irreparable. This gives me a time limit of about a month to test with a CPU. I chose the Ryzen 7 5700G, which is on the supported CPUs list.
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, the board could make more progress now. Was a metal shroud bit shorting something out??? Now the board can keep the CPU fan running and displays the POST code 00 (fault with the CPU.) The board has an 8pin + 4pin connector for the CPU while both my PSUs only have an 8pin (one is split into two 4pin connectors). I read that the board should boot fine with only an 8pin connector, and that you can even try powering it with just the 4pin connector. I tried all combinations of plugging in a 4pin connector and got the same result. I also tried both PSUs to double check.
Then we move onto inspecting the board for damage. Here are some pictures. The compression made the images pretty blurry. I can upload closer shots of any specific area.
I couldn't see any obviously blown components. So I pulled out an out analogue ohmmeter and started probing capacitors. I hope I'm using it right, please let me know. Each time I change the resistance range, I touch the leads together and use the adjuster knob to set the resistance to 0. Then I plug the black lead into COM and keep that on the I/O shield. I plug the red lead into OHM and touch that to the capacitor legs on the back of the board. When measuring, I start at the lowest resistance range and work my way up until I get a read.
There is a cluster of 5 capacitors near the CPU power connectors (seen in image 3.) 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 (touching COM to the negative lead). 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 5.) 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. Is 0 ohms on the negative lead of a capacitor normal? Am I measuring it wrong? Or 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 also probe MOSFETs and buck converters. If I need to replace components, I have access to a hot air station and soldering tools through school.
Where should I be looking now? Any suggestions appreciated. Thank you.
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