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.

 

[Tetras]

(cable came with PSU a few years back I assume, never used it before)

Are you certain that it came with your PSU? These cables are not interchangeable between brands and sometimes not even within a range.

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 ?

Is your original cable the same?

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

You mean it doesn't turn on AT ALL (i.e. no fans, no nothing)? If so, it makes me wonder if the PSU's protections are being triggered because the cable doesn't belong to it?

 

[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!

 

[no_1_dave]

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.

You should never do that.
You've been lucky this time, but those cables can be different for every brand and every generation of PSU.

You could have fried your whole system