T43 wouldn't power up (FIXED) - Pic Warning

[natz]

Thinkpad Crew

Thought I'd share with anyone that may be facing the same fault as i did with my T43.

upon powering the laptop, the battery indicator would flash for a slit second then immediately die!

charger was tested ok which leads me to believe the system board, anyway I disassembled the laptop and when removing the board from the chassis I then flipped it over -

as doing so a nice little capacitor falls off!

I'm no expert with electronics - I thought it was odd that the capacitor showed no continuity.

Anyway soldered it back on and has been fine ever since

see pic below
http://img710.imageshack.us/i/image380.jpg/

[killer]

Welcome to the forums, natz.

Well done for fixing it. Which model of T43 was it, 14" or 15"?

To get round the picture problem (quite a sensitive subject on thinkpads.com) you could post the link rather than the picture itself. It's not too late to edit your posting.

P.S. Which part of Brum are you in? Years ago I lived in Moseley and then in Edgbaston. I still support Moseley Rugby.

[natz]

Welcome to the forums, natz.

Well done for fixing it. Which model of T43 was it, 14" or 15"?

To get round the picture problem (quite a sensitive subject on thinkpads.com) you could post the link rather than the picture itself. It's not too late to edit your posting.

P.S. Which part of Brum are you in? Years ago I lived in Moseley and then in Edgbaston. I still support Moseley Rugby.

Hi Killer,
Thanks for the warm welcome. Birmingham ( Kings Heath ) is my home town, I'm now in Dudley.

14" is the model

cheers

[poshgeordie]

Looks like an Intel GPU'd T43 - the best one IMHO!

I'm slightly scratching my head as to why a "capacitor" like this would make that much difference - if it is a cap. The reason I say that is that it shouldn't conduct but also "all" these caps tend to do is to smooth supply line volts and I wouldn't have thought it would make that much difference.

I've got one of these boards in work so I'll have a look tomorrow and see if I can find out what the component is / does.

[Tim M]

I'm slightly scratching my head as to why a "capacitor" like this would make that much difference - if it is a cap. The reason I say that is that it shouldn't conduct but also "all" these caps tend to do is to smooth supply line volts and I wouldn't have thought it would make that much difference.

I've got one of these boards in work so I'll have a look tomorrow and see if I can find out what the component is / does.

Scrutinizing the photo, I think it may not be a capacitor (seems to have more than two leads). Perhaps it's some sort of voltage regulator or solid state relay?

[poshgeordie]

Just checked the Intel GPU'd board I have here and it's a smoothing capacitor across a supply line.

When you replaced the cap, the white line has to be towards the left - pointing towards the GPU. if it's the other way round it may burn out or go short circuit.

[rkawakami]

Seems to be an electrolytic (polarized) capacitor; the white line on the component as mentioned by poshgeordie and the "+" on the board next to the cap. Since it's located near a 2.5uH inductor, my guess is that it has something to do with one of the voltage rails (1.8V, 2.5V, 5V, etc.). There's an identical inductor, even labeled L11, on the T23 motherboard that is related to the surging fan problem; essentially a system power defect. There appears to be two 180uF caps connected in parallel from one side of the inductor to system ground.

It's possible that the lack of a capacitor may be fooling one of the power controller chips into thinking that the voltage is not present or at the correct level and is preventing the system from powering up.

A good capacitor, when measured out-of-circuit, should not show constant continuity. If it does, then it's internally shorted. However a large (in uF value) polarized capacitor can be verified somewhat by the following:

- ohmmeter in auto range mode or set to Mohm scale
- connect the leads across the cap and you may see a varying "resistance" reading that changes from low ohms and goes to near infinity
- once the resistance reading becomes stable...
- reverse the leads across the cap and you should definitely see a varying measurement that starts out near 0 ohms and gets close to infinite ohms

[natz]

Looks like an Intel GPU'd T43 - the best one IMHO!

I'm slightly scratching my head as to why a "capacitor" like this would make that much difference - if it is a cap. The reason I say that is that it shouldn't conduct but also "all" these caps tend to do is to smooth supply line volts and I wouldn't have thought it would make that much difference.

I've got one of these boards in work so I'll have a look tomorrow and see if I can find out what the component is / does.

Interesting feedback, wow you know your stuff!

it is the ATIX300 GPU ( noticed the laptop gets very hot underneath!)

here is a more close up pic of that component

http://img269.imageshack.us/i/capcroppe ... ropped.jpg

[poshgeordie]

Ha - makes me look like a plonker trying to be a smarta*s!!

Until now I never realised that the Intel GPU is identical looking to the Intel Northbridge on the ATI boards!

Those chips do get very hot indeed.

Thanks for that and I'm an older (and wiser!!) man,...

[natz]

No problem.

another pic in full of the T43 board..


http://img38.imageshack.us/i/image379d.jpg