abit AN7 motherboard failing during POST, need help

By maurilax
Jun 7, 2006
  1. first off i have a 450watt power supply, amdxp chip(2.6?ghz i think), abit an7 mobo, and some 2 sticks of mushkin ram 512mb.

    ok so heres the problem. over the last 2 years since ive had this rig it has randomly rebooted 4 or 5 times with the siren type sound from the motherboard speaker. also whenever i have had to add new hardware be it sata HDD or dvd drives whatever when i try to reboot i get 2-3 seconds of fans spinning and then it will die again and the siren sounds goes off. this also happened during power outages etc, but not when i restarted through windows or the reset button on the case. normally after anywhere from 20 mins to 2 hours i could reboot and it would just seem to kick over and startup and then it would run fine for days. anyway i went to change a video card today and decided that i wanted to get to the bottom of this problem.

    after a few hours of powering off and rebooting i couldnt get it to boot and it fails at post about halfway through the power up sequence with a CF error, which has to do with the readwrite status of the bios (from what i have read)

    anyway i took off the mobo and made sure it wasnt touching the case etc. cleaned all the part. still no boot. right now all i have connected are the processor 1 stick of ram and the heat sink. took the heat sink off before and noticed the thermal pad was pretty much destroyed (after 2 years use). i know i need a new one or some paste. but my question is, is it possible that it wouldnt post/boot because of lack of heatsink paste? im pretty sure the chip isnt fried and the power supply is definatly good as tested on another setup. any suggestions? do amd or abit have a fail safe so that if the processor isnt connected to a heat sink through the pad/paste it wont post or boot? please help. thanks

    first post sorry if it is confusing
  2. DonNagual

    DonNagual TechSpot Ambassador Posts: 2,404

    I am just going into a meeting, so I didn't really read the details. I'll come back to you in a few hours, but the first thing you need to do is get some thermal paste.

    Without it, the CPU can't transfer its heat to the heatsink. You currently have NO thermal paste/pad? Don't try to turn on your system any more, until you have some thermal paste in there!!
  3. maurilax

    maurilax TS Rookie Topic Starter

    there is "some paste" but it is pretty close to being metal on metal connection, some of the paste is on the processor and seems a bit corroded, i have some paste on its way out here but most of the people i have talked to that would know about this stuff tell me that the processor doesnt have time to over heat in the 4-5 seconds that the power is on and thus it cannot be an overheating issue. which leads me back to the question of, does either amd or abit have some way of telling if there is a good connection between the processor and heatsink, and could this cause it to fail?

    i guess ill know in 2 hours when the paste gets here!!

    any help is appriciated
  4. iss

    iss TechSpot Chancellor Posts: 1,994

    What kind of 450 wattt PSU is it? generic or brand name? and if a brand name what is it?
  5. maurilax

    maurilax TS Rookie Topic Starter

    its actually 420watt sorry about that. the brand is turbolink im pretty sure. it came with the case. it works with my pentium4 board and chip by the way
  6. KingCody

    KingCody TS Evangelist Posts: 992   +8

    that is a garbage PSU, and it would be wise to replace it, however that's not your current problem.

    I have that board on my old system (it's a great board), and the "siren" as you put it is indeed caused by an overheating CPU. 4-5 seconds is 2-3 more time than is needed for a CPU to overheat.

    as if the thermal pad wasn't bad enough by itself, you killed any effectiveness it has left by removing the heatsink. whenever you remove the heatsink, you need to apply need thermal paste before you attemp to boot up again.

    make sure you are grounded, then carefully remove the heatsink and CPU. clean the bottom of the heatsink and the top of the CPU die with isopropyl alcohol. the die is exposed on an AthlonXP so be very carefull not to damage it. once the alcohol has dried off put a very small dab of thermal paste on the CPU die (not on the heatsink) and rub it on with your finger inside a plastic bag (do not touch it with your bare skin). then reseat the CPU and heatsink.

    good luck :)
  7. maurilax

    maurilax TS Rookie Topic Starter

    after reading some posts here i figured that i was going to have to change the thermal paste which was when i took the step to remove the heatsink.

    before you replied to this post however i had just finished putting on the new paste. i cleaned both the heat sink and the exposed area of the cpu using the isopropal and a credit card and let it dry. i used the stain left over from the old pad, and filled it in with a light layer of new thermal paste. how long should i let it set? i have one more tube of paste, did i mess up by applying it tothe heatsink and not the cpu? thanks for the help, and towmarrow i can yell at all the guys who told me it would take 10 mins for the cpu to overheat.

    on a side note the power supply may suck but i really like the case, it has a glass panel on the outside which impressed all the chicks at college with all the lights. it also has two fans blowing air out and since i dont over clock and never wanted to bother with extra cooling, the case helps just that much. ive never had a problem with it over the last 2 years and i have 3 hdd and 2 dvd drives runnin not to mention usb stuff. /shrug
  8. DonNagual

    DonNagual TechSpot Ambassador Posts: 2,404

    Shouldn't be a problem that you applied to the heatsink, as long as you didn't use too much. Should be applied paper thin.

    You don't need to let it set for too long. It is actually the heat that helps it set properly anyways. I'd go ahead and see if you can fire it up now.

    As for the PSU, I'd agree that it would be a very worthwhile investment to get something more reliable. Up to you of course, but when a PSU does die, it has a nasty habbit of taking parts out with it.
  9. maurilax

    maurilax TS Rookie Topic Starter

    would putting on to much paste cause it to overheat still?....i am getting the same error and i put a heafty amount on. i am going to try and do it again thiner.

    another thought? i would i know if the cpu was actually fried?

    EDIT:after the tries booting i got a new post error code of AF. then 3 moe tries later it booted. yayayayay. maybe it is possible that the excess paste melted away? should i still go back and change it?

    THANK YOU all for your help. you guys rock
  10. DonNagual

    DonNagual TechSpot Ambassador Posts: 2,404

    Too much thermal paste can potentially be dangerous, as it can short out some pins/bridges on the cpu/motherboard. It does conduct electricity very well.

    Read here on how to correctly apply thermal paste:

    Have a read. If you applied too much, it may be a good idea to redo it again.
  11. maurilax

    maurilax TS Rookie Topic Starter

    just to follow up

    my pc was running great for a day then it crashed once and booted up fine. then i moved it and couldnt get it to boot.

    after purchasing a new power supply (the old one still works but thanks to this forum i now know it sucks) everything is running great. luckily i had some best buy gift cards and grabbed an antech truepower 430. it was a little expensive to buy in a store but at least i didnt have to wait for it to ship

    this was most defiantly a power supply issue, thanks to everyone who helped here
  12. wolfram

    wolfram TechSpot Paladin Posts: 1,967   +9

    Cheap power supplies can be very bad, and can even burn your entire system. Nice new Antec psu!
  13. KingCody

    KingCody TS Evangelist Posts: 992   +8

    rest assured that is a good PSU you bought. I have an Antec TruePower 380w PSU, they are almost silent, the voltages are extremely stable, and the current is rock solid. nice choice of PSUs :)
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