Thermistor readings wildly chaning?

GHoosdumGHoosdum Icrontian
edited August 2003 in Hardware
I just set up my secondary rig with the Barton 2500+ and my A7N8X. When I first boot up, if i check the hardware monitor in BIOS, the processor temp reads in the 60s. If I leave it on for a while and reboot and check again, the temp reads in the 40s... in other words, the temp only seems like it's high on cold boot. What's going on here?

Comments

  • Straight_ManStraight_Man Geeky, in my own way Naples, FL Icrontian
    edited August 2003
    Ok, thermistors only show stable temps when they are warm to a degree, first off, and secondly resistance to temp can stablilize differently on startup as resistance and voltage mixes stabilize. Temp increase for some is inverse to resistance, and I have seen circuits that invert to calc temp. Before the circuit is stable with a steady feed from capacitors, you get an uneven voltage flow, this tosses the rest of the ciruit off temporarily. If you can, let it run for a while and see if part of this is a need to burn in the circuit by using it. Once it has been used for a while this will disappear a bit on a new board.

    Part a new baord thing, part a power circuit stabilizing, and part that the circuit literally is more stable once used for while. 24-72 hour burnin time.

    If it fluxes DURING use after you have run it actively for a week or so, you might have somkething bad on the board, but a startup is a very responsive circuit both warming up to temp and flow right and minor power fluxes inside the machine being amplified. The startup flux should be reduced some after that time, though not totally-- 5C to 8C less flux if it is a good circuit after it is burned in or use tested.

    Most mfrs that sell consumer boards do not burn them ALL in for 24-48 hours before shipping these days, they spot sample and burn in a few adn look at more only if problems. You got one that was not burned in before shipping-- that is part of it anyways.
    Every temp circuit I have ever used tempers its fluxing on startup to a more stable and smaller flux some (15-30 percent of first start flux is normal startup flux DROP) after a week or so.
  • GHoosdumGHoosdum Icrontian
    edited August 2003
    The board is about 6 months old, though, and I never noticed it doing this with the old processor in there, only with the new Barton. Is it using the motherboard's thermistor or the processor's?
  • jj Sterling Heights, MI Icrontian
    edited August 2003
    Fluxing a little bit for stablizing yes..but a 20 degree flux in the wrong direction...no. I suggest you do it again. Note the temp on cold start then run for a half hour or so and reboot again. Do you have air conditioning. My thought is the vent is by your computer and that caused the temp to go down. Or you have a really sweet fan..were can I by one. :-)
  • Geeky1Geeky1 University of the Pacific (Stockton, CA, USA)
    edited August 2003
    consider RMAing it. ASUS sent me a replacement A7N8X Deluxe that consistently reads 30-50*F too low (e.g. it'll tell me my 2.37GHz 2500 is @ 69*F in an 80*F room with air cooling) so now I have to RMA that one too...
  • NoFutureNoFuture In a 3D world...
    edited August 2003
    I think the BIOS uses the board's sensor...
    Anyway, I don't see any pont in RMAing it, ASUS's sensor readings are always F*cked up, mine is too...

    You should use another program like MBM. There is a thread over at Nforcershq.com in the ASUS forum wich will guide you on how to configure MBM to read your temps correctly.
  • Geeky1Geeky1 University of the Pacific (Stockton, CA, USA)
    edited August 2003
    nofuture, only my 2nd A7N8X has this problem... the first one died (SNDS) and the replacement they sent me has this problem... none of my other ASUS boards have done this, ever...
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