Question Dead motherboard Asrock B75 Pro3

Oct 21, 2019
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Hi,

A friend came to me with hes computer after he suddenly rebooted while gaming, unfortunaly he never started again.
First there was a bootloop, start (no screen, no bios beep), cpu fan spinning a fiew seconds and reboot, and so on...

He boughed the same motherbord, put all the components on it and though it was job done, but no. still the same, exept that with another cmos battery the fans continu spinning, no reboot.
I got both mobo's now ans also the rest of the components, exept the disc drive, so i can use them to learn.

Cmos reset got no affect and there is till no bios beep on a clear motherbord, exept cmos battery, cpu, cpu fan, and cmos speaker.
I have no other PSU to try but i tryed hes PSU in another computer and this one was working fine. I tested every single pin from the output atx and the voltage was correct.
I replaced the Bios chip with a new one (spi flash memory). Just maybe this, i tested voltage comming out of the the pins, and i saw that only 4 out of the 8 pins had a 3.4v. (not totaly sure of this but i saw a video that showed voltage on all 8 pins).

This are the hardware parts:

Motherboard: Asrock B75 Pro3
CPU: Intel Core i5-3450
GPU: MSI GeForce GTX 1050 Ti 4GT LP
RAM: 2x Corsair 16GB • DDR3 • 1.600Mhz
PSU: Corsair CX500
Windows 10 on a 500Gb SSD and a secondary HDD inserted (He boughed another computer and putted both of them in the other computer so i dont know exactly the models)

What could i do more to find out the problem on those boards?

Thanks
 
Oct 21, 2019
2
0
10
You should breadboard the system with only the bar minimum, leaving the discrete GPU out, one stick of ram and see if you can get to BIOS. Then see if you can boot to OS GUI. How old is that PSU?
Hi,
I just tryed this one. Clean board, one stick of memory (try them both one by one) and speaker. No CPU.
Got nothing. PSU shuts down after a fiew seconds. (tryed with CPU fan on in case the mobo strugled over that point but result remain the same)

About the question of the age of the PSU... i cant answer on this one. All i know is that i was able to start another computer with this PSU