[SOLVED] New 850W PSU Not Powering On (MBU & GPU Lights on)

[stuart_fagan]

I have just purchased an RTX 3080 FE and I have decided to upgrade my current 650W PSU to an 850W PSU. I installed the new PSU wired everything up -only installing the new cables for the MBU and PCI-E- I left the old CPU and SATA cables in (for ease of installation). I turned on the power switch (on the PSU) and the MBU and GPU lights turned on. I then tried the on switch (on the PC) but nothing happened. I did hear a click (maybe a relay in the PSU) but still no fans or power to display.

I decided to install my old 650W PSU and everything worked as normal.

I have overclocked my CPU to 5Ghz, could this be a possible issue due to not resetting my overclock but changing PSU?

Or do I maybe need to bite the bullet and install the new PSU with every new cable?

Or could my MBU be out of date (I don't think this is likely) (MBU: ASRock Z370 Extreme4)

Thanks in advance.

 

[AntonyLovric]

Sorry, not quite understanding, you only connected the motherboard ATX power (24 pin), and GPU PCIE Power (8 pin)? but didn't plug in the drives or the other ATX (12V1) for CPU power on the motherboard?

(Or Did you use the old cables from the previous motherboard - that could be risk?)

 

[DSzymborski]

I have just purchased an RTX 3080 FE and I have decided to upgrade my current 650W PSU to an 850W PSU. I installed the new PSU wired everything up -only installing the new cables for the MBU and PCI-E- I left the old CPU and SATA cables in (for ease of installation). I turned on the power switch (on the PSU) and the MBU and GPU lights turned on. I then tried the on switch (on the PC) but nothing happened. I did hear a click (maybe a relay in the PSU) but still no fans or power to display.

I decided to install my old 650W PSU and everything worked as normal.

I have overclocked my CPU to 5Ghz, could this be a possible issue due to not resetting my overclock but changing PSU?

Or do I maybe need to bite the bullet and install the new PSU with every new cable?

Or could my MBU be out of date (I don't think this is likely) (MBU: ASRock Z370 Extreme4)

Thanks in advance.

Eeek, do you mean you used the old CPU and SATA cables? Because those ain't universal. Pinouts are very different from company to company sometimes even to similar models. They're only universal on the side that connects to the components. The best case is that nothing happens; the worst case is that it can destroy the PSU and anything you connect it to. Power coming in where it's not supposed to is a Very Bad Thing. You'll only know once you do this properly.

 

[stuart_fagan]

Eeek, do you mean you used the old CPU and SATA cables? Because those ain't universal. Pinouts are very different from company to company sometimes even to similar models. They're only universal on the side that connects to the components. The best case is that nothing happens; the worst case is that it can destroy the PSU and anything you connect it to. Power coming in where it's not supposed to is a Very Bad Thing. You'll only know once you do this properly.

Yeh, unfortunately. Thought I was saving time. Now it appears it was a mistake. I appear to have gotten if lightly.

So if I try to install again, don’t be lazy and install all the new cables?

stuart.

 

[stuart_fagan]

Sorry, not quite understanding, you only connected the motherboard ATX power (24 pin), and GPU PCIE Power (8 pin)? but didn't plug in the drives or the other ATX (12V1) for CPU power on the motherboard?

(Or Did you use the old cables from the previous motherboard - that could be risk?)

Yeh. The only cables I changed were the MBU 24-pin cable and GPU cable. Left the toner cables from previous PSU kit.

 

[AntonyLovric]

Why not swap the others? Are you sure they are the same between PSUs/vendors? I hope all is ok, if everything boots with the old PSU things might be fine.

What happens with the paperclip test on the new PSU when it's out of the PC on it's own?

 

[stuart_fagan]

Why not swap the others? Are you sure they are the same between PSUs/vendors? I hope all is ok, if everything boots with the old PSU things might be fine.

What happens with the paperclip test on the new PSU when it's out of the PC on it's own?

I thought I was saving time. Didn’t try the paper clip test. The new PSU gives power to the motherboard as the lights go on, but doesn’t boot. So the PSU appears fine.
I just need to install all new cables and not just some.

 

[jonnyguru]

Yeh. The only cables I changed were the MBU 24-pin cable and GPU cable. Left the toner cables from previous PSU kit.

Yeah. That's exactly what you SHOULD NOT DO.

 

[AntonyLovric]

I thought I was saving time. Didn’t try the paper clip test. The new PSU gives power to the motherboard as the lights go on, but doesn’t boot. So the PSU appears fine.
I just need to install all new cables and not just some.

I wouldn't be surprised if the old PSU cable pins aren't the same size as the new PSU sockets, it would be the equivalent of not plugging in the 12V1 cable. (If they did make contact it would have worked (same polarity) or smoked (if new PSU had reversed 12V & GND).

I am surprised that a standard (like Molex) isn't applied to modular PSU cables.

 

[--SID--]

What's the make and model of the psu's?

 

[stuart_fagan]

What's the make and model of the psu's?

One is EVGA G3 650W and the other Corsair RM 850x.

 

[--SID--]

That psu's do not have the same pinout. You cannot use EVGA cables with a Corsair psu and vise versa. Only use the cables that came with the psu!!