Question PC PSU

[Scottyaj]

I am trying to troubleshoot a PC Power supply. This is a 24 pin configuration. The PC will not boot up and the power supply fan is not running. I have taken the power supply out of the PC and used the paper clip test. The power supply seems to work fine. The fan runs and all the voltages check out with a multimeter. One question i have is the gray wire (PS-OK) signal. This pin has 5 Volts DC measuring to common but when i measured this pin to common while connected to the motherboard the voltage is 0 volts DC. I was wondering do i still have a PS problem or could the motherboard be the problem. Any help would be appreciated.
Thanks

 

[Darkbreeze]

With the power supply connected to the motherboard, including both the ATX 24 pin and any required EPS/CPU 4, 4+4 or 4+4+4 pin connectors, have you tried eliminating the case switch from the equation and simply jumping the pwr pins on the motherboard to trigger the power good signal and cause the PSU to turn on. As outlined here:

https://www.gamersnexus.net/guides/2011-jumping-a-motherboard-without-power-switch-button

Otherwise, these are the recommended steps for testing which go just a little beyond ONLY using a paperclip.

View: https://www.youtube.com/watch?v=ixcWCrYpw3Y

As important might be, what are the full system hardware specs including motherboard model, EXACT power supply model and approximate length of time that unit has been in service and all other core hardware such as CPU, memory kit, graphics card, number and type of drives, etc.

 

[Scottyaj]

With the power supply connected to the motherboard, including both the ATX 24 pin and any required EPS/CPU 4, 4+4 or 4+4+4 pin connectors, have you tried eliminating the case switch from the equation and simply jumping the pwr pins on the motherboard to trigger the power good signal and cause the PSU to turn on. As outlined here:

https://www.gamersnexus.net/guides/2011-jumping-a-motherboard-without-power-switch-button

Otherwise, these are the recommended steps for testing which go just a little beyond ONLY using a paperclip.

View: https://www.youtube.com/watch?v=ixcWCrYpw3Y

As important might be, what are the full system hardware specs including motherboard model, EXACT power supply model and approximate length of time that unit has been in service and all other core hardware such as CPU, memory kit, graphics card, number and type of drives, etc.

Yes I have tried eliminating the power switch by using a jumper across the power switch terminals on the motherboard with no success. The model of the power supply is EVGA 750B3 p/n# 220-B3-0750. The PSU has been in service for a couple of years. The motherboard is an ASUS model. The graphics card is PNY GeForce 1660 OC 6GB GDDR5 PCIe 3.0. Also a 1 TB WD Hard drive.

 

[Darkbreeze]

Absolutely horrible power supply. The B2 series were fantastic. The B3 units were complete and total trash.

Relevant review information regarding this model here: https://www.tomshardware.com/reviews/evga-750-b3-power-supply,5229-11.html

While I cannot definitively say that this is the cause of your problem, I CAN definitively say that these B3 units were complete pieces of crap and should never have been sold nor used by anybody with any system regardless of the hardware requirements.

Knowing the model of the CPU and motherboard would be extremely helpful as well. For the purpose of dating how long it has actually been in service and the probable initial quality if nothing else.