New PC build,no power

custardy

okay,so Im scratching my head here

New build thats shows no signs of power

• MSI X570-A pro motherboard
• Ryzen 5 3600
• Corsair CX 550M PSU
• 16GB DDR4 3200 Corsair ram
• GTX 1660
• MSI Gungnir 100 case

All of the above brand new.

Tried in and out of the case.
Paperclip tested the PSU and checked the voltages . all as expected
Removed CPU and checked for damaged pins,all good.
Tried removing all but CPU,then adding components.
No power showing,no fan spin ,no LEDs lit on the motherboard.
Checked,refitted,rechecked everything I can think of. by passed the case power switch,reset CMOS
Stand offs look fine with no danger zones I can see. Tried a different kettle lead.
Anyone got any ideas?

Ta

DoaM

Either the PSU has a fault (i.e. the short-circuit protection is detecting even a minor load as a short), or the motherboard has a short which is tripping the PSU. Try measuring the PSU voltages with the mobo connected. (Apologies if that's what you've already done - that's not how I've read your OP).

Also, are the stand-offs the insulated type? (Sometimes you can get a short without even realising, even if it all looks OK).

dan958

I think you've done pretty much every check you can do. You got any other motherboards or power supplies you can test with?
As the psu has the voltages, and it doesnt even work when you try bypassing the powerswitch, I'm thinking maybe a dud mobo

I also wouldnt expect any shorts if you built it outside the case

SidneySmutt

After removing all the cables from the supply to the MOBO. Power on. Does the PSU come to life? There is usually a green LED letting you know power is hitting the BUS. At least this way, you can take the MOBO out of the equation, and just concentrate on the PSU.

custardy

dan958 said:

I think you've done pretty much every check you can do. You got any other motherboards or power supplies you can test with?
As the psu has the voltages, and it doesnt even work when you try bypassing the powerswitch, I'm thinking maybe a dud mobo

I also wouldnt expect any shorts if you built it outside the case

I thought the same and got a replacement (assuming I could send back the other)
Exact same with a replacement board (same model,same supplier so potentially a bad batch but ....)
I fitted my old cooler master 550W PSU to the same result.

custardy

DoaM said:

Either the PSU has a fault (i.e. the short-circuit protection is detecting even a minor load as a short), or the motherboard has a short which is tripping the PSU. Try measuring the PSU voltages with the mobo connected. (Apologies if that's what you've already done - that's not how I've read your OP).

Also, are the stand-offs the insulated type? (Sometimes you can get a short without even realising, even if it all looks OK).

I hadnt measured with the mobo connected as I was wary of risking the mobo.
I had wondered about using the paperclip test with the mobo connected to fire up the PSU and see if that brought it to life?
I have reached out to MSI but who knows how long a reply will take.
I cant help but feel theres a fault on the motherboard but 2 faulty motherboards?

Edit: take it back. Got a reply from MSI. So lets see what they come up with. No doubt they will know if its a common issue though doubt they will say if it is

custardy

SidneySmutt said:

After removing all the cables from the supply to the MOBO. Power on. Does the PSU come to life? There is usually a green LED letting you know power is hitting the BUS. At least this way, you can take the MOBO out of the equation, and just concentrate on the PSU.

Nothing at all. No combination of connections can get me any life from the mobo

DoaM

So the LED on the PSU comes on OK (with no mobo connected)?
When you connect up the mobo, does the PSU LED still come on or not? If not then my previous point stands - there's either a PSU fault or a mobo fault. If the LED does come on then the fault probably lies with the mobo (or something else causing a short). However the fact you've tried another PSU suggests that the PSU is OK.

I agree though that the chances of there being 2 mobos causing the same fault (whilst possible) is remote. That's why I suspect it is something else.

dan958

Tried different PSU cables? (like the motherboard connector, and cpu power). Chances of them causing any issues is so unlikely though.

custardy

dan958 said:

Tried different PSU cables? (like the motherboard connector, and cpu power). Chances of them causing any issues is so unlikely though.

The new psu is modular and the old PSU is fixed so I cant swap cables unfortunately.
I'll be honest I cant think of anything but two DOA motherboards.
I can see an RMA in my future

Neil_Jones

Looking at the picture of the board it has the normal 24 pin on the right hand side, then an eight block and a four pin top left.

You have connected all these?