Last night I was stress testing the overclock I could achieve on my graphics card using eVGA Precision and eVGA OC Scanner. I had GPU-Z open at the time as well. I was running below 80deg C @ 810-875MHz core clock (shader synced to 2x core) and I did not modify the standard GPU voltage of 1.05V. After running for ~30 minutes, I bumped the core clock to 900 and still did not go past 86deg C (90deg C was the limit I was watching for). After about 8-10 minutes of testing, the entire system shut off, and within 5 seconds I heard a single loud pop. I shut down the power to the supply and unplugged the box.
This is a brand new build and I completed a quick examination of the motherboard and did not see any burst caps. The GPU was too hot to handle and I will complete a more detailed examination this evening. In the meantime, I was curious if anyone could give me some pointers on where to look? I have a decent amount of CPU/memory OC experience but have never touched the GPU before and I typically err on the side of caution; I have never had a sudden major failure of a component before. The details of my build follow:
ASUS Maximus IV GENE-Z/GEN3 (BIOS 3103)
i5-2500K @ 4.6 (1.35V) w/Thermaltake Frio
8GB (2x4GB) Corsair Vengeance 1600MHz 9-9-9-24
eVGA GTX 560 Ti 448 Core Classified Ultra
Corsair Force GT 120GB
I don't think there's any doubt it's power related, either the power supply itself or blown power regulators on the GPU or M/B, you'll have to troubleshoot to pin it down, and unfortunately sometimes when a power supply itself goes, it can take other components with it.
I completed a quick examination of the motherboard and did not see any burst caps.
Did you smell an electrical burn smell?
Did you check the voltage regulators on the motherboard?
They're located underneath those L shaped black heat sinks, if one burned enough to pop you'll be able to see it.
I did a quick visual of the mobo and didn't see anything obvious. From my experience as an electrical engineer (breaking things) I should have smelled it if an IC blew. I will be testing the PSU tonight in addition to a more thorough visual inspection. If both of those come back okay, I will be testing the PSU with the mobo without ancillary components.