I can't seem to find many references to my particular issue online, so I thought I'd post here and ask. I've recently started overclocking the following budget build, which I put together in January:
1 x Rosewill R218-P-BK Black SECC Steel ATX Mid Tower Computer Case
2 x Link Depot 39" SATA II Cable with 2 Right Angle Connectors Model SATA-39-90B
1 x ECS A885GM-A2 (V1.1) AM3 AMD 880G SATA 6Gb/s ATX AMD Motherboard
1 x PowerColor AX6850 1GBD5-DH Radeon HD 6850 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity
1 x ePOWER EP-600NE-XV 600W ATX12V v2.2 / ESP12V v2.92 Power Supply - OEM
1 x AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core Processor HDZ965FBGMBOX
1 x G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBRL
1 x HITACHI Deskstar 7K1000.C 0F10383 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
1 x SilenX EFZ-120HA3 120mm Fluid Dynamic Bearing Performance Heatpipe AMD/Intel CPU Heatsink
I've been able to overclock this processor to 4.0GHz at 1.475V with temps staying below 65C under full loads for extended times. It passed a full Prime95 stress test running overnight without issue, and I've had no problems with BSODs, corruption, or any other of the usual signs of instability.
However, I have been unable to "cold boot". If I leave the machine off for about an hour or so, and then attempt to boot, it fails. I get a double flashing HDD access light, which I haven't been able to find any diagnostic codes for in my motherboard manual. The machine will boot normally after reflashing CMOS to stock settings, and it seems to be able to boot with normal voltage and a slight overclock to 3.6GHz. The computer will also restart normally at the 4.0GHz stable settings; the problem only occurs if the computer is off for some period.
The lack of other issues while overclocked, along with the inability to boot only after some time, leads me to suspect my motherboard or PSU is not up to snuff, which would not be a surprise, since the components were picked for best reviews at a low pricepoint.
Has anyone else encountered this type of problem, and any ideas on what might be contributing to the problem? I'm considering replacing the PSU in particular, since if that's causing the machine to be unable to boot at anything but stock, it might cause me further problems as it ages.
Breadboarding looks interesting; is there something in particular I should be looking for?
Also, what kind of cooling problems are you thinking? As mentioned, temps remain with normal ranges during operation, and this problem only seems to show up if I leave it off for about 30 minutes...there could be some kind of weird thermal expansion going on, but I don't think a CMOS reflash would fix it then.