Toshiba Satellite - Locks up when plugged in

[dood]

Interesting one here. I've got a Toshiba Satellite that will lock up almost as soon as you plug it into AC. If you run it off the battery, it won't lock up at all and runs fine until the battery runs out.

Tried a brand new ac adaptor and still has the issue. Doesn't seem to be overheating, and I even pulled it apart and put new AS5 on the CPU heatsink. Didn't find anything else noticibly wrong when I was in there, either.

Any thoughts?

[mockingbird]

Did you check for a lint carpet between the heatsink and the grill?

[dood]

Originally Posted by mockingbird

Did you check for a lint carpet between the heatsink and the grill?

Cleaned everything when I had it apart.

I've found some other people online having the same issues - noone has been able to solve it. Tried BIOS updates, no go. I'm thinking it might be a piece of hardware that's disabled when running on battery, and then turns itself back on when plugged in and causes the laptop to lock up. The laptop locks up whether it's in Windows or not.

[stj]

bad caps in the hv stepdown probably.

[mockingbird]

Did you try removing components? (i.e. modem card, wifi card...)

[Wizard]

Carefully check the SMD electrolytic capacitors, especially small ones in critical control circuits for power MOSFETs.

Cheers, Wizard

[insomnia]

could be bad caps alright but i would also check to see if it is a bad joint on the dc jack

[Rainbow]

Just fixed one Satellite A300. This is caused by a bad cap. A big one - NEC/TOKIN 0E907 (900uF/2.5V) under the CPU. Mine had 900uF but probably lost some of its magic, resulting in >100mV ripple on CPU power. Adding 1x 100uF and 5x 10uF ceramic caps fixed the problem.

[Biancocf]

Hello everybody , im new here , but i promise to do my best to help on this fantastic forum! , i need a little help here , i remove this capacitor now the mobo does not boot , how can i dessolder the capacitor from anither board without destroy it?

[Biancocf]

Originally Posted by Rainbow

Just fixed one Satellite A300. This is caused by a bad cap. A big one - NEC/TOKIN 0E907 (900uF/2.5V) under the CPU. Mine had 900uF but probably lost some of its magic, resulting in >100mV ripple on CPU power. Adding 1x 100uF and 5x 10uF ceramic caps fixed the problem.

can you help me to solve this problem? i need to change this capacitor and it's too weak to temperature... please it's my first bad service here...

[severach]

The only good method I've found for quickly and safely removing large 2 terminal SMD parts like caps and diodes is with 2 soldering irons. One in each hand and a tantalum cap lifts off in seconds with minimal heat. A SMD hot air gun and one soldering iron works also but the part gets a lot more heat before coming off.

The cap can be put on the same way with 2 irons but the result doesn't look good and the part gets a lot of heat while fussing with the position. Removing the solder from one pad and using 1 iron usually produces a higher quality result.

[ablacon64]

Go for Rainbow tip. That huge capacitor is usually responsible for that. Keep in mind that it has four soldered terminals in it. I had success by preheating the motherboard (150ºC) and then using a hot air rework station to remove it.
Two soldering irons won't do for that one (or at least will be very difficult).
But in my case I replaced then with 4 330u 2.5v tantalun SMD capacitors.

[Biancocf]

Originally Posted by ablacon64

Go for Rainbow tip. That huge capacitor is usually responsible for that. Keep in mind that it has four soldered terminals in it. I had success by preheating the motherboard (150ºC) and then using a hot air rework station to remove it.
Two soldering irons won't do for that one (or at least will be very difficult).
But in my case I replaced then with 4 330u 2.5v tantalun SMD capacitors.

can you post a picture ? i want to see the finish job , the space is too short to 4 caps here , if possible of course...

[Biancocf]

Wooooww!! it work's !!! i change a little bit the prescription but it's perfect!!
i put 10 ceramic caps on right side and 4 470u tantalum on left side and now it's like a new one , thankyou everybody , now i want to post a pic of the job to help others , can someone help me to post a pic ? what max specs of the pic please...

[retiredcaps]

Originally Posted by Biancocf

what max specs of the pic please...

Use the manage attachment functions (below text area) and please do not post inline.

Max jpg is 2000x2000 and around 4MB.

[Biancocf]

i help this help others , thank's

[ablacon64]

Originally Posted by Biancocf

can you post a picture ? i want to see the finish job , the space is too short to 4 caps here , if possible of course...

Unfortunately, I made this fix some time ago, the notebook is with the client. But I made a (terrible) drawing. Hope it helps.

[ablacon64]

Originally Posted by Biancocf

can you post a picture ? i want to see the finish job , the space is too short to 4 caps here , if possible of course...

I had the opportunity to solve another one with that same problem, this time I took some pictures. Hope it helps.

The notebook is a Toshiba Satellite A305-S6872.

The first image shows the capacitor removed, board cleaned.
The second, new solder added to the pads.
And finally, the finished job.

[azry]

Thanks all for that pictures... i never thinking to do this before!

[unlockdev]

I Hav toshiba L300 blinking power adapter i thinks the problem in the caps to cos i check the power mosfet ist oki ???