Power Supply Problem

By CTugwell ยท 8 replies
Jul 6, 2006
  1. Hi

    My laptop has decided not to play game when you try to power it with an AC adaptor. The unit works fine on battery, but will not power with either of my AC adaptors. On one adaptor the light flashes when plugged into the laptop, on the other the light goes out when plugged into the laptop.

    Has anyone any ideas on why this might be or has had the same problem?

    Appreciation in advance.

  2. pcaceit

    pcaceit TS Rookie Posts: 315

    Hi. Are you trying to power it from mains with battery removed? cause that probably wont work. if you have two identical adapters that are recomended for your laptop and they should not be displaying different behaviour so i would say that one of them is faulty.

    But if they are not identical then one could be flashing because it has detected no battery or is charging, and the other one probably goes out because it cant detect a battery to charge.

    give more details please cause i dont quite understand the situ
  3. CTugwell

    CTugwell TS Rookie Topic Starter

    Laptop power supply problem

    Hi, thanks for your reply

    The problem exists whether the battery is on board the laptop or not. The adaptors are universal adaptors and are different makes, which is probably why they are behaving differently.

  4. pcaceit

    pcaceit TS Rookie Posts: 315

    The power suppy ratings for laptops are very specific and i doubt that a standard universal adapter is capable of powering the laptop.

    check the power requirements on the bottom of the laptop and the power ratings on the universal adapter.

    laptops will probably require between 12 to 25 volts and probably 1.5A minimum (dont jump on me guys im not that far out)

    when you mention universal adapter i think of 3 to 12v at about 500ma maximum. and i can guarantee that it wont power a laptop.
  5. pcaceit

    pcaceit TS Rookie Posts: 315

    There's also a polarity issue as well so you should use recomended adapter for your laptop or you could dammage it
    so i think there's nothing wrong with your laptop.
  6. CTugwell

    CTugwell TS Rookie Topic Starter


    Does quite ring true - as both universal adaptors (both with voltage settings) had worked with the laptop perfectly well, now neither of them work with the laptop so I think the laptop is to blame???!!!!
  7. pcaceit

    pcaceit TS Rookie Posts: 315

    The power supply circuit on the laptops mainboard has some protection on it against reverse polarity and wrong voltages. Those universal adapters generally do not give steady voltage and current because they are unregulated, so you get spikes and more often you get the wrong voltage, if you test the voltage with a meter and switch through the voltages, you will see what i mean.

    If the Psu on the laptop is burned out it might still work with charged battery but you just wont be able to charge the battery in the laptop.

    could also be that the socket on the laptop has broken away from the board.

    Unfortunately the psu is usually part of the laptops mainboard so check it by using the correct psu if it works then your'e lucky, but if not you will need a new Mainboard.
  8. CTugwell

    CTugwell TS Rookie Topic Starter


    Many thanks - this seems to make sense, but probably means big expense! Won't be using a universal adaptor again.
  9. korrupt

    korrupt TS Rookie Posts: 716

    You using the right voltage adapter? And have you tried different powerpoints at different houses to rule that out?


Topic Status:
Not open for further replies.

Similar Topics

Add your comment to this article

You need to be a member to leave a comment. Join thousands of tech enthusiasts and participate.
TechSpot Account You may also...