Pc boots with 500w psu but not 850w or 1000w

[Slidfungus]

I've made a similar post about this before, but this seems to be something else than what I concluded, I just got a new 850w psu because my pc wasn't booting after a gpu upgrade, but when I used my old 500w psu it did, as any reasonable person would, I assumed my psu was broken in some way, so I got this new one. It has the exact same issue, no display and the vga light on the motherboard is on. I can't just use the 500w because it's not enough power for my system. I've never heard of a problem like this anywhere before but it very clearly seems gpu related, I just don't understand why it would work flawlessly with the 500w and not 850 or 1000

[johnt]

specs? model numbers? photos?

[Robchil]

I hope you replaced all cables.. 

 

[Slidfungus]

1 minute ago, johnt said:

specs? model numbers? photos?

The new psu is a corsair rm850x, the gpu I just got is an xfx rx 6950xt, I'm using a ryzen 5 3600 in an msi b450-a pro max with 32gb of ddr4 3600Mhz. In the picture the power supply is outside the case because I didn't want to spend time cable managing for it to not work

[Slidfungus]

1 minute ago, Robchil said:

I hope you replaced all cables.. 

 

I did, but my previous psu was also  corsair rmx series, so I wouldn't have mattered

[Robchil]

5 minutes ago, Slidfungus said:

I did, but my previous psu was also  corsair rmx series, so I wouldn't have mattered

use the first 8 pin on those cables with 2.. and don't use the second.. 

 

replacing cables ALWAYS matters, there is no guarantee two generations and or different power of same brand have same PSU side pin out.. if they are produced in different location that's enough. 

 

and start with only connecting CPU 24pin and PCIE cables. 

 

[sabgog]

13 minutes ago, Slidfungus said:

I've made a similar post about this before, but this seems to be something else than what I concluded, I just got a new 850w psu because my pc wasn't booting after a gpu upgrade, but when I used my old 500w psu it did, as any reasonable person would, I assumed my psu was broken in some way, so I got this new one. It has the exact same issue, no display and the vga light on the motherboard is on. I can't just use the 500w because it's not enough power for my system. I've never heard of a problem like this anywhere before but it very clearly seems gpu related, I just don't understand why it would work flawlessly with the 500w and not 850 or 1000

I don't get what you are saying here - are you saying that the PC boots with the new GPU but you don't want to run it with the 500w power supply? Or does it not boot at all with the 500w or 850w power supply with the new GPU in it?

[Slidfungus]

Just now, sabgog said:

I don't get what you are saying here - are you saying that the PC boots with the new GPU but you don't want to run it with the 500w power supply? Or does it not boot at all with the 500w or 850w power supply with the new GPU in it?

The pc boots with the 500w power supply, but I can't use it for anything because 500w is not enough for this system, it will not boot with either of my corsair power supplies(rm1000x, rm850x)

[sabgog]

I think Robchil mentioned it above, but you are for sure using only the cables that came with the new PSU, and only the ones listed as PCIe and plugged into the corresponding plugs on the PSU correct? You can't use another PSUs cabling with a new one, and the ones listed as PCIe and CPU have different pinouts. If the PC boots with an older and smaller power supply, a wiring issue seems like about the only thing that it could be.

 

[Slidfungus]

1 minute ago, sabgog said:

I think Robchil mentioned it above, but you are for sure using only the cables that came with the new PSU, and only the ones listed as PCIe and plugged into the corresponding plugs on the PSU correct? You can't use another PSUs cabling with a new one, and the ones listed as PCIe and CPU have different pinouts. If the PC boots with an older and smaller power supply, a wiring issue seems like about the only thing that it could be.

 

I used all new cables, wired everything properly as I've been told, and nothing ever changes, this whole situation has been going on for about a week now. Trust me, I've tried every solution I could find, I've never seen anything like this on any forums or support articles and even if I end up having to return the gpu I want to find out what is causing the problem

[Alex Atkin UK]

58 minutes ago, Robchil said:

replacing cables ALWAYS matters, there is no guarantee two generations and or different power of same brand have same PSU side pin out.. if they are produced in different location that's enough.

You definitely shouldn't make assumptions but to suggest you ALWAYS need to replace them is patently not true, if you check beforehand that they are the same type.  Such as when I went from an RM850x to an RM1000x.

[Robchil]

7 hours ago, Alex Atkin UK said:

You definitely shouldn't make assumptions but to suggest you ALWAYS need to replace them is patently not true, if you check beforehand that they are the same type.  Such as when I went from an RM850x to an RM1000x.

better safe than sorry. 

[vBunnee]

@Slidfungus
Did you find a solution for this? I'm having a similar issue. My new 1000w RM1000e doesn't work and motherboard loops between cpu and Dram lights whereas if I use my old cv550w PSU, it works right away.
I even did an RMA for the PSU but does the same thing. It works sometimes weirdly. It'll boot maybe 1 out of 15 times after resetting CMOS and stuff. Trying to find a solution.