Random shutdowns, suspect bad temp sensors

By mrbiggs
Jan 25, 2008
  1. Recently I've upgraded to an 8800GT, got a new Biostar nForce4 board, and new 600W Rosewill PSU. Yes I know Biostar and Rosewill aren't exactly top quality, but they should get the job done. Long story short, failing Antec PSU fried old DFI mobo and 6800GT.

    Here I am now, thinking I'm finally back up and running, but I start getting random shutdowns. They're due to the mobo's auto shutdown protection. At a limit of 60C it wont even finish booting windows. At 70C limit I can game for 2 hours, quit to desktop, go downstairs for ten minutes, come back and its shut down (in other words, HUH?). I've got three 120mm case fans all running at FULL blast, 2 of them getting full power from 4pin molex and one in the PSU set to High. MBM5 and speedfan both report an idle CPU temp of 93C, chipset 70C, and PWMIC 127C. The CPU and chipset heatsinks are both cool to the touch on idle. I guess this means either the sensors are wrong or each heatsink is failing to do ANY cooling and is instead insulating (doubt that. 1 factory installed, one self). I guess I will feel them under load next...

    GPU idles at a mind-soothing 48C. Aside from disabling the auto-shutdown protection, what can I do here? Thoughts on the validity of the temp sensors? Thanks.

    EDIT: Further testing reveals Prime95 + Compressing a DVD = heatsinks become warm to the touch, temps reported do not change.
  2. mailpup

    mailpup TS Special Forces Posts: 6,964   +355

    You didn't mention it so let me touch this base: when you installed the processor onto the new motherboard, did you clean off the old thermal compound from the heatsink and processor and reapply fresh compound?
  3. porsche911r

    porsche911r TS Rookie Posts: 37

    i think it might be a faulty mobo...
  4. mailpup

    mailpup TS Special Forces Posts: 6,964   +355

    Could be. Do the temps reported in the BIOS match what is reported by those utility programs?
  5. mrbiggs

    mrbiggs TS Rookie Topic Starter

    Yup I cleaned it up with alcohol and installed it correctly.

    The highest I've ever seen the BIOS read was 38C right after one of the auto shutdowns.
  6. porsche911r

    porsche911r TS Rookie Posts: 37

    that temp seems fine but if ur getting random shutdowns it normally means that there is somthing wrong with the psu or the mobo..see how it goes and if benchmarks are running stable then u got urself a cooling running system!!!!!
  7. mrbiggs

    mrbiggs TS Rookie Topic Starter

    I agree, the BIOS temp does look correct. But if the auto shutdown is managed by the BIOS, why does it seem to be responding to the false temperatures? (BTW, first boot of the day and CPU was at 27C - 15 seconds later in windows and its back to good old supposed 93C)

    I want to be able to correctly monitor my temps so I can try out a bit of OC'ing with my new hardware, any way I can correct this? I'm wondering if it has anything to do with the fact that this mobo is a replacement and if somehow settings from my old DFI are messing with things.
  8. mailpup

    mailpup TS Special Forces Posts: 6,964   +355

    You have a point. If you are using the old hard drive, you should do a Windows repair or if that doesn't turn out satisfactorily, reinstall Windows and either way, install the drivers for the new motherboard if you haven't already.
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