P850GM Gigabyte & 4070ti Sup

[eekfek]

So, I've connected a second 8pin cable to PSU to power the GPU ie two 8pins going into the 16pin converter. (cable came with PSU a few years back I assume, never used it before)

When i power PC I get nothing, no lights not even into bios. I thought maybe the PSU blew/broke.

Reverting it all back to original state, PSU still works fine with old 3070 and one 8pin.

I'm thinking it's probably the new cable I've attached but I noticed the 8 pin going into PSU only uses 7 Pins of the 8 ! not being the most technically minded is that possibly the problem ?

Any help welcome! cheers.

 

[eekfek]

Forgot to update.. but thanks for replying Tetras.

So, mate brought round a box of new EVGA cables which at first looked exactly the same as the Gigabyte ones but with 8 pins both ends etc.

They actually didn't fit into the PSU so I had to slighlty separate the plastic on the pins which made them slot in.

Booted PC up and worked a treat. It's ran stable for a good few days.

++

As for that cable, sometimes the PC would start with the old cable plugged in but most of the time dead as a doornail. So you are probably right in saying the PSU didnt like it as it wasn't from the original cables!