USB short, possible fried board

[c-manning4]

Recently had a friend build a rig, had it up and running for 2 days, plugged in a flash drive and the PC shut down.

The power light on the board flashes once every second now, and the PC won't turn on. After doing some research, it seems like case USB ports causing a short is fairly common. After removing the USB connection to the mobo, the same issue persists. Removing the GPU and all case connections, leaving behind only one stick of RAM and the CPU, the problem still persists. Is it possible that this USB short fried the brand new mobo?

All components are brand new:
Strix z270e
Gtx 1060
2 sticks of ddr4
7th gen i7
650W PSU

 

[Paul NZ]

Did you install the standoffs before you installed the mobo? If you didnt it'll short on the case

Dont think a USB short is fairly common. I've built 4 desktops, and they've never had a USB short

 

[jasonkaler]

That's a pretty bad motherboard if it can't tolerate a USB short.
I've personally shorted out my USB ports many times by messing about with my own circuits and have never fried a motherboard.
I just get a popup in the corner of the screen to the effect of "USB over current detected".

As Paul said, it's possible something else shorted the motherboard, but I would not totally rule out the USB device.
Just because it's unlikely, doesn't mean it was not the cause.

 

[c-manning4]

Seems like a higher-end, more modern mobo. I find it odd that a USB short could've done this either, but here we are. The standoffs are in place on the mobo. Any suggestions?

 

[jasonkaler]

Was there any smell?
Do any chips look burnt or faded?

A single blinking LED on the motherboard without it powering up usually means a short somewhere.
Try disconnecting absolutely everything other than the cpu and psu - see if the motherboard beeps when there is no ram.

 

[c-manning4]

Everything disconnected except the psu and cpu, still just blinks.

 

[Mark RM]

Check the actual USB ports on the rear of the board and see if the pins in them are bent around and crossed.

 

[c-manning4]

Ports on the back look okay. Very puzzling. Brand new parts, PC ran fine for a couple days. Pop in a USB device and it is just dead.

 

[smorizio]

have you tried clearing the cmos. the mb may have see the dead short and turned off for safty. sometime when it does some mb need there bios cleared to post again. if the green power good led is blinking then your power supply is at fault now and not the mb. try a test power supply.

 

[FluxCap]

Take the MB out and breadboard it to make sure it is not shorted.