Help diagnosing pc! Runs for ~ 1 second then shuts off!

What I've tried:

Jumped PSU with paperclip. Stays on.

Tried another confirmed working PSU. Same problem.

Tested power switch by jumping +- on mobo. Same problem.

New mobo. Same problem.

Disconnected GPU. Same problem.

Tried each (2) RAM in each slot (4). Same problem.

Tried confirmed working RAM in each slot. Same problem.

Now I am at a loss. I will probably try an old CPU as I wait for responses.

Thanks.

Submitted July 30, 2017 at 01:26AM by kweber313 http://ift.tt/2hchScY