I know this is ancient…w/e.
I had the same power issue with one of my eight TX1 boards. I replaced the capacitor as @Trumany suggested but the problem persists. The only way I can power the board on is by continuously removing and re-inserting the power cable into the board. Seemingly at random, the board will power on after a number of tries.
Can Nvidia provide any other test points or information I can use to debug this? I’m a year out of my RMA window.