[SOLVED] What did I do to my PC???

Solution
Most likely would say you damaged your motherboard by shorting out power to something it wasn't supposed to go to.
I would assess the cost of motherboard replacement along with other possibilities like the CPU, PSU, etc. and balance that against the age of the system and cost to replace components with newer equipment.

Aside from that, might pull the PSU and test it to see if it still turns on such as by the paperclip test.

DSzymborski

Curmudgeon Pursuivant
Moderator
Hard to say exactly without looking at the board closely, but from the results, it sounds like you shorted something, which can have unpredictable results, some very bad or even fatal. The I/O shield isn't just there for cosmetics and without one, you need to be extra careful.
 

punkncat

Polypheme
Ambassador
Most likely would say you damaged your motherboard by shorting out power to something it wasn't supposed to go to.
I would assess the cost of motherboard replacement along with other possibilities like the CPU, PSU, etc. and balance that against the age of the system and cost to replace components with newer equipment.

Aside from that, might pull the PSU and test it to see if it still turns on such as by the paperclip test.
 
Solution

InvalidError

Titan
Moderator
Yup, must have killed a chip by shorting it in a way it wasn't designed to handle. Unplug all non-essential device and see if you can get boot that way as some peripherals may also have been damaged if you shorted 12V to IO/3.3V/5V/other. If your computer boots, then at least one of your non-essential peripherals may have been damaged, plug them back in one by one to see whether they fail to show up or cause the PC to shut down or fail to boot.