ASUS laptop won't charge

[Tim Downie]

I've got a friend's ASUS M5200 laptop that I've offered to look at.

It works fine when connected to it's power supply but dies instantly if the
power is removed. There are only ever two lights on on the front of the
laptop, one for the mains supply and one for the hard drive. The battery
light never comes on. The power meter in Windows does identify the battery
and shows it as having zero charge.

I've tried battery recalibration and a new battery has also been tried but
neither helps, it still refuses to charge. More in hope than in expectation
I've opened it up to have a look around but there's nothing obvious to see.

I'm guessing something has gone wrong with the internal charging circuitry.

Is there anything else I can do or have I come to the end of repair options
(short of motherboard replacement)?

Tim

 

[Ken]

I've got a friend's ASUS M5200 laptop that I've offered to look at.

It works fine when connected to it's power supply but dies instantly if
the power is removed. There are only ever two lights on on the front of
the laptop, one for the mains supply and one for the hard drive. The
battery light never comes on. The power meter in Windows does identify
the battery and shows it as having zero charge.

I've tried battery recalibration and a new battery has also been tried
but neither helps, it still refuses to charge. More in hope than in
expectation I've opened it up to have a look around but there's nothing
obvious to see.

I'm guessing something has gone wrong with the internal charging circuitry.

Is there anything else I can do or have I come to the end of repair
options (short of motherboard replacement)?

Tim

Remove the battery and see if you can measure the voltage present at
the terminals the battery connects to while the charger PS is plugged
in. If you see no voltage there, it is a safe bet that the internal
components of the charging circuit are at fault. If there is voltage
there, you might consider the possibility of the terminals not making
proper contact with the battery.

 

[Tim Downie]

Remove the battery and see if you can measure the voltage present at
the terminals the battery connects to while the charger PS is plugged
in. If you see no voltage there, it is a safe bet that the internal
components of the charging circuit are at fault. If there is voltage
there, you might consider the possibility of the terminals not making
proper contact with the battery.

The contacts all look undamaged and are soldered securely to the
motherboard. I'm not sure which contacts do the charging and what voltages
to expect so I've not done that (yet).

Tim

 

[Tim Downie]

It can be as simple as an open fuse (but it'll be a surface-mount
soldered
in fuse). It sounds like the charging circuitry isn't doing its job.
Look for
surfacemount MOSFETs that have failed if the fuse isn't the problem
(or if the fuse, when replaced, blows again).
This is where I have to admit to a considerable amount of ignorance. What would a surface mounted fuse look like and would it be visibly blown?

Tim
(apologies for stupid quoting. Using my wife's Vista disabled laptop).

 

[Ken]

It can be as simple as an open fuse (but it'll be a surface-mount
soldered
in fuse). It sounds like the charging circuitry isn't doing its job.
Look for
surfacemount MOSFETs that have failed if the fuse isn't the problem
(or if the fuse, when replaced, blows again).

This is where I have to admit to a considerable amount of ignorance. What would a surface mounted fuse look like and would it be visibly blown?

Tim
(apologies for stupid quoting. Using my wife's Vista disabled laptop).

No insult intended, but it sounds like this task might be beyond your
abilities. First most laptops are not easy to disassemble. You could
very well do more damage than good. If this computer is worth anything,
you might try to find someone who has some skill repairing electronic items.

 

[Tim Downie]

No insult intended, but it sounds like this task might be beyond your
abilities. First most laptops are not easy to disassemble.

I've taken a few apart. What's more, I've put most of them back together again. ;-)

You could
very well do more damage than good. If this computer is worth anything,
you might try to find someone who has some skill repairing electronic items.

It's several years old and an "extra" laptop in the household. I doubt it would be economically worth trying to get repaired unless the cost is low enough.

I won't deny that it's probably beyond my skills. I was just hoping there might be something obvious that was within my ability.

Tim

 

[D Yuniskis]

Hi Tim,

I've got a friend's ASUS M5200 laptop that I've offered to look at.

It works fine when connected to it's power supply but dies instantly if
the power is removed. There are only ever two lights on on the front of
the laptop, one for the mains supply and one for the hard drive. The
battery light never comes on. The power meter in Windows does identify
the battery and shows it as having zero charge.

I've tried battery recalibration and a new battery has also been tried

When the "new" battery was installed in the machine, did the battery
light come on? What did Windows report re: the battery's condition?
(was it really a *new*, CHARGED battery that you used?)

but neither helps, it still refuses to charge. More in hope than in
expectation I've opened it up to have a look around but there's nothing
obvious to see.

Bents pins (or pins that are stuck "retracted" in the battery
connector)?