[SOLVED] Is my psu faulty?

[Davidino]

Recently I bought an asus P5G41T-M LX
I wanted to test my R9 280x, cuz im selling it and the person wanted to know if it functions. I didnt have a mobo that supports the R9 280x so I bought that one. When I tested it it didnt turn on (using a cx500m), but with another psu (atx psu from HP pc) it did turn on. My cx500m isnt dead because I litteraly used it in my previous build and im 100% sure it works fine.
But why didnt my pc turn on with the cx500m?

 

[RARRAF]

not enough wattage for the R9 280 maybe its old.

 

[Davidino]

not enough wattage for the R9 280 maybe its old.

I also tested the mobo without gpu and it didnt turn on

 

[Satan-IR]

So P5G41T-M LX and R9 280x turned on with HP PSU and didn't turn on with the cx500m, right?

Have you tried shorting the POWER ON pins on the motherboard (bypass the case power switch)?

Have you tried breadboarding the sysetm? Taken the mobo+CPU+one stick of RAM out of the case and seen if they power up with the cx500m PSU?

It wouldn't show if PSU is good and delivering nominal voltages on different rails and so on but in order to check if the PSU is totally dead or not you can do the paperclip test too. If fan doesn't start spinning it's probabyl dead.

Illustrated instructions for the test here.

 

[rolli59]

"I didnt have a mobo that supports the R9 280x " This, really any mobo with PCIe x16 slot should support the card except few old ones with PCIe v1.x like the one you bought!

 

[Davidino]

"I didnt have a mobo that supports the R9 280x " This, really any mobo with PCIe x16 slot should support the card except few old ones with PCIe v1.x like the one you bought!

Thats what most people say, but like with my gtx 650 2gb: it didnt show display on my asus p5k-e but it did on my msi 770-c45

 

[Davidino]

So P5G41T-M LX and R9 280x turned on with HP PSU and didn't turn on with the cx500m, right?

Have you tried shorting the POWER ON pins on the motherboard (bypass the case power switch)?

Have you tried breadboarding the sysetm? Taken the mobo+CPU+one stick of RAM out of the case and seen if they power up with the cx500m PSU?

It wouldn't show if PSU is good and delivering nominal voltages on different rails and so on but in order to check if the PSU is totally dead or not you can do the paperclip test too. If fan doesn't start spinning it's probabyl dead.

Illustrated instructions for the test here.

I have tried breadboarding the system and the paperclip test isnt needed because im litteraly using the cx500m in my other build and it works fine. What do you mean with shorting the power on pins though?

 

[rolli59]

Thats what most people say, but like with my gtx 650 2gb: it didnt show display on my asus p5k-e but it did on my msi 770-c45

what CPU are you using?

 

[Satan-IR]

Because of this:

My cx500m isnt dead because I litteraly used it in my previous build and im 100% sure it works fine.

Used not use. What I got from that is it used to work and isn't working anymore and you think it's OK because it used to work.

The POWER_ON pins are the pins on the motherboard that the case power button basically shorts on the MOBO to tell the PSU to start delivering power and turn system on. Disconnecting the case button from them and shorting them would rule out a faulty case power switch. But since your original system (whatever the specs are) is working now it's moot.

 

[Davidino]

what CPU are you using?

On the lga775 motherboards an intel quad q8300 and on the am3, an amd phenom ii x4 970 BE

 

[Davidino]

Because of this:

Used not use. What I got from that is it used to work and isn't working anymore and you think it's OK because it used to work.

The POWER_ON pins are the pins on the motherboard that the case power button basically shorts on the MOBO to tell the PSU to start delivering power and turn system on. Disconnecting the case button from them and shorting them would rule out a faulty case power switch. But since your original system (whatever the specs are) is working now it's moot.

Oh okay

 

[Karadjgne]

Nvidia is backwards compatible on the pcie side from current to pcie 1.1. Only pcie 1.0 is incompatible, uses a different power design.

Some years ago, right around the time of pcie 2.2, amd changed its power circuitry on its gpus, so cards like the r9 200 series are only compatible back to pcie 2.2. You'd need an older amd/ati card like the x1600 to use on pcie 1.1-2.1.

The asus p5k-e is pcie 1.1, so it's highly doubtful it'll work past post with a r9 280x, but will work ok with a gtx 650, both of which will also work with a legacy bios.

The msi 770-c45 is pcie version 2.3 (pcie2.0 bus spec) so will support anything in the R9 series and newer, or any nvidia that's not pcie 1.0 specific.

But none of that relates to the fact that if you connected the Corsair psu correctly, and it didn't work, but the HP did, the Corsair is toast.

 

[Davidino]

Nvidia is backwards compatible on the pcie side from current to pcie 1.1. Only pcie 1.0 is incompatible, uses a different power design.

Some years ago, right around the time of pcie 2.2, amd changed its power circuitry on its gpus, so cards like the r9 200 series are only compatible back to pcie 2.2. You'd need an older amd/ati card like the x1600 to use on pcie 1.1-2.1.

The asus p5k-e is pcie 1.1, so it's highly doubtful it'll work past post with a r9 280x, but will work ok with a gtx 650, both of which will also work with a legacy bios.

The msi 770-c45 is pcie version 2.3 (pcie2.0 bus spec) so will support anything in the R9 series and newer, or any nvidia that's not pcie 1.0 specific.

But none of that relates to the fact that if you connected the Corsair psu correctly, and it didn't work, but the HP did, the Corsair is toast.

Oh ok, thanks for informing me.