Hardware Error after 1s

[heliosh]

The CPU is the last part i would suspect. Which mainboard do you have?

[LaurV]

Originally Posted by Prime95

though nowadays thermal problems just translate into throttling not freezing

My thinking too. Especially the fact that the crash is in the first seconds (not enough time for the heat to ramp up) indicates either a power issue or some too high clock (losing the "track", watchdog kick). The GPU you have consumes nothing there (I mean compared with the old Titans we use here, or even with an 1080). My money would be on the power supply or the chipset (mobo). If you pass the memtest for a hour or so, try reducing the clock to stock or lower. Does the mobo have on-board video card? If so, remove the GPU, connect the monitor to the on-board connector and try again. If it pass, then your power supply is crap. Use a gold or a platinum one, from a good company. A silver or bronze power supply will have lower efficiency at higher consumption, and will not be able to ramp-up fast when the "bulldozer" starts (my experience is more with intel cpu's, anyhow). Here we would hook an oscilloscope to the voltage bars and see what they do, but I don't know if you have one.

Another idea, do you get a blue screen when the toy crashes? What the message of the bsod says? (most of the time, it will indicate exactly the problem). If not, can you run the Event Viewer after restart and look inside for the last errors (you will have a lot, take it slow and don't get worry, most of them mean nothing, or just mean that the microsoft guy who programmed there was a bit more zealous).

[heliosh]

Originally Posted by Prime95

though nowadays thermal problems just translate into throttling not freezing.

If it's the CPU, then yes. But some AM3/AM3+ mainboards are notorious for having underdesigned and insufficient cooled voltage regulators. And problems in this regard exactly express in this way.
That's why I've asked (twice) what mainboard he was using.

MOSFETs have a very low thermal mass and can overheat within fractions of a second.