5750g has blue power light but no other signs of life...

imac
imac Member Posts: 6 New User
edited November 2021 in Aspire Laptops
The laptop was working, was shut down then refused to come back up; the blue light comes on but nothing else happens - no lights, no fan, no display. I tried disconnecting the hard drive and memory, reset the BIOS, reseated all the main cables but got nowhere. Is there anything else that might save the old thing from being recycled?

Thanks in advance,

Answers

  • JackE
    JackE ACE Posts: 45,080 Trailblazer
    >>>was shut down then refused to come back up>>>

    Was it a normal or forced shut down? If forced, why?

    Jack E/NJ

  • StevenGen
    StevenGen ACE Posts: 12,476 Trailblazer
    edited November 2021
    imac said:
    The laptop was working, was shut down then refused to come back up; the blue light comes on but nothing else happens - no lights, no fan, no display. I tried disconnecting the hard drive and memory, reset the BIOS, reseated all the main cables but got nowhere. Is there anything else that might save the old thing from being recycled?

    Thanks in advance,
    Iain

    Is the power problems happening when the laptop is on battery power only or is it with battery and power adaptor plugged in? Does the laptop work with just the power adaptor plugged in and the battery out? As it could be that the battery alone can't power the laptop and needs replacing. Try to run the laptop on the power adaptor only without the battery. If this does not work then it could be that the internal "Power Board" is faulty and needs replacing. Check the battery power is at 10.8V and the adaptors output is 19V if they are up to specs as and if they are working then it could be your Power Board that is the problem, if all these parts are working then you need to take your laptop to a technician that has all the tools to diagnose your laptops power problems that are complex and could be in other parts and circuitries of your motherboard that need replacing.

    The battery, power adaptor and power board details and Acer part numbers are as follows for the Aspire 5750G: 

    OEM Batteries

    OEM Adaptors

    OEM Power Board



  • JackE
    JackE ACE Posts: 45,080 Trailblazer
    >>>was shut down then refused to come back up>>>

    Was it a normal or forced shut down? If forced, why?

    Jack E/NJ

  • imac
    imac Member Posts: 6 New User
    Thanks folks.

    The shutdown was normal, it failed to post/boot the next time I tried to use it.
    I get the blue light on the power button and the front edge, regardless of whether it's on battery or powered.
    I'll check out voltages in a few spots to see if that implicates the power board and report back.
  • JackE
    JackE ACE Posts: 45,080 Trailblazer
    (1) Unplug the charger
    (2) Remove the battery pack
    (3) Press and hold the power button for about 2 minutes
    (4) Plug the battery pack back in
    (5) Plug the charger back in
    (6) Don't try to turn the laptop on. Watch the battery charge LED.
    (7) The battery charge LED may first be unlit. Then should flash. Then turn steady orange. Then steady blue. This may take up to 8 or more hours.
    (8) Only after battery charge LED turns steady blue, try to turn it on again.

    Jack E/NJ

  • imac
    imac Member Posts: 6 New User
    JackE said:
    (1) Unplug the charger
    (2) Remove the battery pack
    (3) Press and hold the power button for about 2 minutes
    (4) Plug the battery pack back in
    (5) Plug the charger back in
    (6) Don't try to turn the laptop on. Watch the battery charge LED.
    (7) The battery charge LED may first be unlit. Then should flash. Then turn steady orange. Then steady blue. This may take up to 8 or more hours.
    (8) Only after battery charge LED turns steady blue, try to turn it on again.


    I thought we were on to something there; I don't remember seeing the charge LED lit before (it did light orange and blue whilst charging); now I have an unresponsive laptop with a fully charged battery:)
  • imac
    imac Member Posts: 6 New User
    StevenGen said:
    imac said:
    The laptop was working, was shut down then refused to come back up; the blue light comes on but nothing else happens - no lights, no fan, no display. I tried disconnecting the hard drive and memory, reset the BIOS, reseated all the main cables but got nowhere. Is there anything else that might save the old thing from being recycled?

    Thanks in advance,
    Iain

    Is the power problems happening when the laptop is on battery power only or is it with battery and power adaptor plugged in? Does the laptop work with just the power adaptor plugged in and the battery out? As it could be that the battery alone can't power the laptop and needs replacing. Try to run the laptop on the power adaptor only without the battery. If this does not work then it could be that the internal "Power Board" is faulty and needs replacing. Check the battery power is at 10.8V and the adaptors output is 19V if they are up to specs as and if they are working then it could be your Power Board that is the problem, if all these parts are working then you need to take your laptop to a technician that has all the tools to diagnose your laptops power problems that are complex and could be in other parts and circuitries of your motherboard that need replacing.

    The battery, power adaptor and power board details and Acer part numbers are as follows for the Aspire 5750G: 

    OEM Batteries

    OEM Adaptors

    OEM Power Board




    It makes no difference if I try to start it on battery, mains with battery or mains without battery. The battery and charger voltages are 12.1 and 19.1 on a rather cheap multimeter; I presume that the battery is slightly high due to there being no load?

    I looked at the power board and there doesn't seem to be much to it; is it possible simulate the correct signal to the motherboard by shorting any of the conductor pairs in the ribbon? Given the front edge LEDs work in response to the button should that steer us away from the power board?

    I'm afraid it's not worth taking to a shop to be looked at/fixed.
  • JackE
    JackE ACE Posts: 45,080 Trailblazer
    Can you reach and re-seat the power board's ribbon cable connector at the mainboard a few times to help clean its contacts?

    Jack E/NJ

  • imac
    imac Member Posts: 6 New User
    JackE said:
    Can you reach and re-seat the power board's ribbon cable connector at the mainboard a few times to help clean its contacts?

    I have some contact cleaner in the shed; I'll give that a go tomorrow, thanks.
  • imac
    imac Member Posts: 6 New User
    edited November 2021
    I tried the contact cleaner, even packed it forward with a slip of paper, but there's no change. I'll have a final poke at it tomorrow, but I fear it's reached the end of the line and is destined for eBay as spares.

    Annoyingly it's only a couple of months since I sent an old chassis and mother board to the CA site for recycling (it had similar issues - but possibly a good switch - that I'd bought for £1 for its screen; I did have to drive an hour out of my way to collect it!). Might keep an eye out for another local bargain donor, but they seem to rare as hens teeth.
  • JackE
    JackE ACE Posts: 45,080 Trailblazer
    Sorry I didn't see your attempt to use contact cleaner. Please don't use it any more as it can attack any plastic parts especially connector wedges for FFC ribbon cables. All that's really needed is physical abrasion from re-seating or perhaps by gently rubbing with a cotton cloth or q-tip perhaps moistened with a bit of rubbing alcohol. 

    Jack E/NJ