Friends PC will not turn on after putting rear side panel on while running

[Derp88]

I am writing this on behalf of my friend. A few days ago he got a new case, after moving the parts in and several hours of troubleshooting with me (He plugged the case power button header into the clear CMOS pins and forgot to plug CPU power in.) Today he wanted to install something into his case for wifi, In doing this though he left the PC on. When putting the rear side panel back on the computer froze and failed to boot up, all that would happen is the fans would spin and a few LEDs in the case came on when he tried turning it on. After, an hour of troubleshooting today which included; resetting CMOS, running with just the motherboard, CPU, PSU, and heatsink and fan outside the case, and checking all connections. It still did not boot, personally, I think when he put the side panel back on it may have made contact with the back of the motherboard and fried the system, if that is possible.

Friends PC Specs:
CPU: I7-6700K
MB: ASUS Z170k
RAM: 16GB DDR4 ADATA
GPU: GTX 980Ti
PSU: Highpower 600 Watt 80+
Case: NZXT S340 Elite
(The PC is an Ibuypower prebuilt)

 

[littleleo]

He could have touched something and shorted the motherboard out. Never work inside your computer case with the system on. Plus I bet he wasn't grounded.

To see what is working I take a motherboard I know works and put it on a test bench with a power supply attached and a switch, and test each component one at a time perhaps he only fried the motherboard.

 

[Derp88]

Update: He just had his motherboard checked out and the entire IO section was fried from a metal to metal contact.