Config: Core 2 Quad Q6600 (previously @3.1GHz, now stock @2.4GHz), 4GB DDR2 Mushkin 800MHz CL4 (2 x 2GB), Gigabyte P35-DS4 (dead on-board NIC & onboard sound), 100Mbit Realtek PCI NIC, HIS Radeon HD 4850 512MB stock, Windows 7 64-bit, Thermaltake 450W PSU, 1TB Samsung Spinpoint F3, 640GB WD AAKS, 250GB Seagate 7200.10, Razer BlackWidow USB KB, Mionix Naos 5000 USB mouse, DVDRW.
Short story: computer boots but freezes not long after booting (both in Windows and in BIOS - USB keyboard and mouse always turn off when it freezes), or continuously power cycles without posting, especially after a reset. I tried a different PSU, disconnecting the 250GB HDD & DVDRW (the other two HDDs are needed for booting), but the same problems occur.
Details:
A few days ago, I found the monitor turned off, the USB mouse & keyboard leds turned off, the computer frozen, with the power and hdd leds on. After a reset I tried to boot the computer, but it would turn on and then immediately turn off again, over and over (no post). I assumed the PCI network card died again, perhaps from a surge caused by lightning (we've been getting heavy raining lately, and this happened before two years ago, the computer wouldn't boot at all until I took the dead NIC out). Next day, I took the NIC out, this time the computer booted into windows, but evetually it would always freeze at some point, idle or not - the keyboard and mouse leds (both USB) always turn off when it does this. I tried to run Batman Arkham Asylum, the computer froze immediately. The computer freezes even in BIOS - with the same symptoms. Sometimes it doesn't even post, it cycles over and over like the first time (but it seems to do this after I reset the computer when it freezes, it doesn't seem to do this after it's been off for a while). I tried putting the NIC back in again, the computer sometimes boots but the same problems occur (maybe it wasn't the NIC that caused this after all).
Another weird thing: when off the computer used to consume ~13W if the PSU switch is on, now it always consumes ~20-21W with the same PSU. So, I suspected the PSU, but I tried a different PSU (very crappy but I used it before to boot the same config) and the same thing happens. So I think I eliminated the PSU as being the culprit, or at least the only culprit.
One colleague suggested taking out a RAM stick at a time, I'll try this when I get home. I suspect the MB or video card (though they both use solid capacitors & all computer fans work OK). I don't have a spare video card to test right now, but I hope I can manage to find one next weekend.
Any advice is welcomed.
Short story: computer boots but freezes not long after booting (both in Windows and in BIOS - USB keyboard and mouse always turn off when it freezes), or continuously power cycles without posting, especially after a reset. I tried a different PSU, disconnecting the 250GB HDD & DVDRW (the other two HDDs are needed for booting), but the same problems occur.
Details:
A few days ago, I found the monitor turned off, the USB mouse & keyboard leds turned off, the computer frozen, with the power and hdd leds on. After a reset I tried to boot the computer, but it would turn on and then immediately turn off again, over and over (no post). I assumed the PCI network card died again, perhaps from a surge caused by lightning (we've been getting heavy raining lately, and this happened before two years ago, the computer wouldn't boot at all until I took the dead NIC out). Next day, I took the NIC out, this time the computer booted into windows, but evetually it would always freeze at some point, idle or not - the keyboard and mouse leds (both USB) always turn off when it does this. I tried to run Batman Arkham Asylum, the computer froze immediately. The computer freezes even in BIOS - with the same symptoms. Sometimes it doesn't even post, it cycles over and over like the first time (but it seems to do this after I reset the computer when it freezes, it doesn't seem to do this after it's been off for a while). I tried putting the NIC back in again, the computer sometimes boots but the same problems occur (maybe it wasn't the NIC that caused this after all).
Another weird thing: when off the computer used to consume ~13W if the PSU switch is on, now it always consumes ~20-21W with the same PSU. So, I suspected the PSU, but I tried a different PSU (very crappy but I used it before to boot the same config) and the same thing happens. So I think I eliminated the PSU as being the culprit, or at least the only culprit.
One colleague suggested taking out a RAM stick at a time, I'll try this when I get home. I suspect the MB or video card (though they both use solid capacitors & all computer fans work OK). I don't have a spare video card to test right now, but I hope I can manage to find one next weekend.
Any advice is welcomed.