Problem with 5742 power cycling intermittantly

broadstairs
broadstairs Member Posts: 11

Tinkerer
in 2014 Archives

My 2 year old Acer 5742 (with an I5 processor) has a strange intermittant issue. Occasionally when I turn it on it will come up with the BIOS screen but does nothing and powers down, then powers back up again and then keeps doing this until I take the battery out. I cannot get it to enter setup if I hold F2 or enter the boot selecvtion using F12, the system does recognise the key press as once the buffer is full it beeps. If I remove the memory SODIMM it will then start normally with no problem. Once the laptop does start working it will work for sometimes weeks before this happens again, other times it will happen again in a day or so.

 

My problem is not power related as it happens on both battery and mains power, I can run Memtest for ever and no memory problems are shown so the memory itself seems OK. The problem only started happening a few months ago and once it does start the system seems to run flawlessly. It runs Fedora Linux 64bit by the way not W7.

 

From searching the forum this does seem to be a problem with some of these laptops and no one (yet) seems to have found a solution.

 

Anyone any ideas please?

 

Stuart

Answers

  • JackE
    JackE ACE Posts: 44,898 Trailblazer

    Sounds like it's overheating and shutting down due to dust buildup around the cpu. Vacuum the intake port. And blow air into the exhaust port. If that doesn't work, the cooling fan may not be working properly.

     

    Jack E/NJ

    Jack E/NJ

  • broadstairs
    broadstairs Member Posts: 11

    Tinkerer

    No this only ever happens from cold, laptop had been off overnight when I turned it on this morning and it did this straight away, once you can get past this issue it will stay up for hours on mains with no problems at all. So far it has only ever happened when it has been turned on from cold.

     

    Stuart

  • broadstairs
    broadstairs Member Posts: 11

    Tinkerer

    One additional thing I should mention is that the initial BIOS display stays on longer by a couple of seconds or so before it power cycles than when it comes up normally and loads from the HDD. So it seems to me that it is doing some kind of H?W check which fails and it power cycles. However as I have said I get no memory errors when running Memtest for a long time, and once up no disk errors or strange errors from Linux (no crashes or kernal panics etc). So whatever is failing keep on failing until I unplug and replug the SODIMM, I have had this now whith the SODIMM plugged into both sockets so its not related to a particular socket.

     

    Stuart

  • JackE
    JackE ACE Posts: 44,898 Trailblazer

    Chips can quickly overheat if the fins are clogged with insulating dust buildup. If due to the insulation the fan thermostat doesn't detect this heat right away, it won't turn on further compounding the problem. If the fan eventually does turn on, it might force enough heat away from the chip to keep it going for the rest of the day.

     

    At any rate, it only takes a few minutes to vacuum and blow out the intake and exhaust ports to test if dust buildup might be an issue here. If not, nothing lost except a few minutes time. Then we can look for other possible causes.

     

    Jack E/NJ     

    Jack E/NJ

  • broadstairs
    broadstairs Member Posts: 11

    Tinkerer

    I will do that but to be honest I just dont believe it is an overheat problem or it would be likely yo happen when left on for hours on end, plus it does not explain why once it happens the only way to get it to boot is to remove & replace the SODIMM, just unplugging the battery wont do it.

     

    Stuart

  • JackE
    JackE ACE Posts: 44,898 Trailblazer

    Well, I suppose there could be a solder break or loose connection somewhere on the MB that sometimes temporarily resolves when you disturb the sodimm area. The bios delay you mentioned earlier also suggests a loose keyboard or video ribbon connection and the ribbons just need to be re-seated in the MB and screen receivers. But i would expect you might sometimes hear a post beep code. I had a similar intermittent, though not identical, 1st-boot-of-the-day issue that turned out to be a video ribbon conductor break in the hinge area --- a simple stress fatigue failure from opening and closing the lid too much --- took several weeks to figure that one out --- drove me nuts.

     

    Jack E/NJ   

    Jack E/NJ

  • broadstairs
    broadstairs Member Posts: 11

    Tinkerer

    Yes this is a weird bug, and it has only happened after a couple of years use! Althought not excessive use, it is a home laptop mainly used by my wife for probably 4 or 5 days a week for a couple of hours at most each day to do email and a bit of browsing. If it was keyboard related I'd have thought  the beep when I hold down either F2 or F12 when the BIOS display shows would not happen, again if it was the video cable I'd expect at least some artifacts on screen or missing stuff.

     

    Stuart

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