I have purchased a new battery for my aspire 3620 laptop, the battery came charged and worked fine, the laptop works fine on ac power but does not seem to be charging my battery, the battery is now critically low but will not charge through ac power, and with the battery in the computer will not power up, when the battery is removed it powers up. Please help

problem in mother board power supply unit check any dry soldering

your f**ked

are you installing it with correct polarity
is one of the battery terminals in the laptop damaged so that it is not making contact

either dead battery or burned out power supply try buying universal one from radioshack or best buy make sure you can return it if its not solving the problem.

if ur charger is ok then u have need to change ur motherboard

As you have tried to replace battery and still new battery is not getting charged in this case it seems there is hardware problem. Circuit which allows battery to charge is not working.

ur battery broken down , so can not keep electric

Take out the battery and make sure you can turn on the laptop with just the AC Adaptor hooked up.

If you can then you know the AC Adaptor is good. Try another known good working battery in the laptop, if the battery charges then you know that the old battery is bad.

If the laptop doesn't charge with a know working battery or a new one then you know that the motherboard is bad.

There is a battery cycle reset in BIOS. try that first. If not see if you still have manufacturer warranty to get a new battery.

Check Acer's website for a BIOS update. I've seen a LOT of laptop's screen issues been related to the power saving settings in the BIOS. Sometimes screens going black very fast and not working properly can be caused by that.

The Power Inverter could also be the problem which you wouldn't be able to repair yourself. If you purchased it at Best Buy you can take it to them and they could get that fixed for you (at a charge if there is no warranty with that).