PSU Works, but not with Motherboard (no lights)

dragonflash · Jun 28, 2016

Hello! This is a new build question.

I have a EVGA 550 G2 power supply and it comes with a 24-pin testing utility. When I plug the testing utility into the 24-pin MB connector and flip the switch, I can feel the fan on the PSU turn on.

I also have an MSI Z170-A motherboard. Whether I have everything plugged in, or just the CPU/fans/RAM/24-pin/8-pin, the PSU fan does not spin up. There is no light indicating the motherboard is receiving any power.

Although I don't know if this would affect the power issue, my RAM is installed in the 2 and 4 slots on the moba, as directed by the manual.

The case I'm using is the Thermaltake Overseer RX-I. The moba is screwed directly to holes on the case and fits well with the back. I assumed this was intentional, and wouldn't short the moba.

Any ideas on what I could be overlooking or what debugging steps I could take?

alexoiu · Jun 28, 2016

Hi, Try testing the board outside the case.

smorizio · Jun 28, 2016

if the mb has onboard video pull the gpu and one ram stick. if the mb posts outside the case check the bios rev if it old use a usb stick and update it.

dragonflash · Jun 28, 2016

I just tried testing the board outside the case, and it has not changed. I also tried pulling off one stick of RAM, but that did not yield any results either.

One thing I did notice was that my PSU's CPU connector has one 8 pin end and one 4+4 pin end. The pins on the 8-pin end match the square-pentagon order on the motherboard's 8-pin slot, but the 4+4 pins do not fit into the PSU's designated CPU slot. However, despite the design mismatch, the 4+4 pin still fits onto the moba, and the 8pin fits into the PSU.

Edit: Both the PSU and the CPU have the same pattern as the 8-pin connector.

dragonflash · Jun 28, 2016

The PSU manual says "connections going to the power supply will not have "break downs" like the EPS (CPU) has a 4+4 on one side and a full 8-pin on the other. Another example is the 24-pin cable, you can see on the PSU side it is a total of 28 pins where the 24-pin connection will go to the motherboard directly."

I have the 8-pin CPU end and the 18+10-pin MB end in the PSU, and the 4+4-pin CPU and 24-pin MB in the motherboard. Still, this works on the 24-pin is connected to the tester, even when the 4+4-pin is still left connected to the moba, but not when the 24-pin is connected to the moba.

dragonflash · Jun 28, 2016

Update: I tried the motherboard with another power supply, connecting only the 8-pin and 24-pin, with CPU and RAM installed, and it still showed no sign of life. Going to replace it as defective.

Search

PSU Works, but not with Motherboard (no lights)

dragonflash

Commendable

dragonflash

alexoiu

Titan

smorizio

Titan

dragonflash

Commendable

dragonflash

Commendable

dragonflash

Commendable

TRENDING THREADS

Latest posts

Moderators online

Share this page