Will not boot - suspected PSU

[julianokessler]

Gentleman,
After a power failure my system started having a hard time booting, and now (one week later) it rarely boots.

Here is how it behaves: the fans, leds and drives are started. However, the monitor receives no signal and the speaker does not beep. Also, holding down the power button for 5 seconds does not shut down the machine. Only the switch in the back of the PSU does it.

I have tried many measures, including disconnecting/reconnecting power conectors, the VGA and the memory sticks, reseting CMOS, removing all non-essential devices.

It is valid mentioning, I believe, that even without VGA and memory, there are no complaining beeps. Seems like the system does not get to the point of testing if the memory and VGA are present.

Another issue is that I do not have a spare PSU to test.

But if I could know for sure, based on those symptoms, that the PSU is at fault, I could just buy another.

Any ideas?


System specs:
PSU - XFX core edition 850W - at least 3 years old
VGA - XFX GTX 1070 - about 2 years old
Mem - 2x 8 GB corsair - at least 3 years old
Proc - FX 9350, I believe - at least 3 years old
MB - Gigabyte GA-970A-DS3P - at least 3 years old

 

[julianokessler]

I managed to borrow another PSU. One that does not have 2x8 pin connectors for the VGA card, but at least can power up the motherboard and CPU. The system now provides the beeps that correspond to graphics card error. Also, the system is now able to power down after holding the power button for 5 seconds. So I guess that's it. The PSU must be at fault.