Given the SLIM details about make, model and AGE it could be another 300 CYCLE battery that is over 18 months old and nothing is wrong except it needs a new battery.
Alright so i'm not normally one to go net-hunting for solutions to my problems, i'm a fairly competent techy and have repaired many strange and unusual problems. But this has me stumped. I just resoldered a powerjack into a Fujitsu Siemens Lifebook (old i know) for a friend. It works fine while the laptop is off. It will charge the battery, you can see the indicator on the little lcd panel filling up the battery as if it is charging. However 9 times out of 10 when I turn on the laptop it will stop charging and run entirely off the battery.
Plugged in, no battery = indicates its plugged in until i press the power button and the lcd panel goes blank as if i pulled the wire out.
Plugged in, with battery = indicates that its plugged in and charging, until I press the button then the 'plugged in' and 'charging' symbols disappear and the battery rapidly drains.
Unplugged, with battery (obv) = Laptop turns on, works fine, but battery rapidly drains.
So i know that it needs a new battery but my friend isnt bothered about it being portable, he just wants it to work when its plugged in. On occasion it will recognise that its plugged in and does charge the battery when its turned on. I'm thinking either faulty connection inside the jack itself for the signal wire or faulty connection to signal wire in the power lead. What do you guys think? Anyone had a similar problem? I do not want to replace anything, I would much rather repair whats already here as he doesn't need it to be portable, just to work. I have repaired chargers and dodgey problems with powering before and am competent with soldering and multimeter testing but I can't seem to get my head around this...