Motherboard with GPU fault - replacement or repair ?

[phillip]

Hi,

I have been looking at replacing/repairing my T41 motherboard and would be grateful to know what the options are. I have been looking on eBay USA and eBay UK at secondhand units but I'm not sure about the quality and reliability of what's being offered.

My board has a faulty GPU connection which causes the system to lock up when moved. I have been considering getting it repaired but from what I've seen of the way the GPU is attached to the motherboard I'm not sure if this is possible. If anyone has any experience of this I would be grateful to know if it can be successfully done and how reliable the repair is.

From what I've read on the net this appears to be a weak spot on the board with this model and I'm concerned about it happening again. I'm considering getting a new machine and having the three year warranty that comes with it but I would like to get my T41 working again in the meantime. I'm lost without it.

Buying a secondhand board seems to be fraught with the same problems in that there will be no way of telling if that GPU will produce the same fault if it's been subject to the same conditions that have caused mine to become faulty.

Do IBM sell new boards and is it cost effective given what refurbished systems are going for at present. Decisions, decisions.

Any information and advice would be much appreciated
Kind regards and best wishes
Phillip

[dyoes]

Wow I just had the same exact problem with my T41 w\ATI 7500 32mb. Be interesting to know if this is a problem with the T41 w/ATI 7500.
http://forum.thinkpads.com/viewtopic.php?t=37989

I upgraded the motherboard to a T43P. If I knew what I know now I would have upgraded to a T42P since its 400mhz fsb and I could have reused my memory and CPU.

The T43P is 533mhz fsb, and DDR2 so if you go this route you need 533fsb CPU, DDR2 memory and PC card/Express card, and long heatsink fan.

Dan
T43P ATI mobility FireGL V3200 ,14.1 XGA LCD, 1gig memory, Hitachi 60gig 7200rpm Hard drive

[rkawakami]

I have been looking at replacing/repairing my T41 motherboard and would be grateful to know what the options are.

Welcome to thinkpads.com!

This thread may be of some help to you if you have not already seen it:

http://forum.thinkpads.com/viewtopic.php?t=33952

Basically it boils down to this: you may be able to use a hot air gun to get the solder balls under the GPU to reflow and properly connect to the motherboard. Some additional damage can result to other components if you are not careful, but seeing how your choices are quite limited (motherboard replacement or expensive repair), you may want to try this.

[phillip]

Hi Dan,

Yes, I saw your post on upgrading and I found it very interesting. It gave me something to think about but I have no idea what the likely costs would be. I would like to take my system up to T42 specs and I like the idea of getting the ATI9000 GPU and a bit more video memory.

I have tried looking on the IBM site to see if they sell system boards and what they may charge but I can't find anywhere that gives this information. There are some boards on eBay which look interesting and I may go for one of those if all else fails. I'm still looking at the repair option but that's probably only because I'm an inveterate fixer and don't like throwing anything away.

Thanks for your help
Kind regards and best wishes
Phillip

[phillip]

Hi Ray,

Thanks for the input. I have looked closely at the GPU daughterboard and can't figure how they mounted it in the assembly process. It can't be subject to any flow soldering as its physical location doesn't allow for that.

It appears that there is a plate-through hole grid array under the GPU which may match up to pins on the board and I had thought of using a pyro pen on the underside of the motherboard to remelt the solder as you suggest.

I don't much like the idea as I would have liked to see how it was fixed in the first place so as to know better what to do. I'm aware that it could still be one of the SMD components close to the GPU but I don't have test gear any more so I can't do any in depth tests.

I guess that there's nothing to lose by trying the heat gun method but I will call a couple of repair companies and see what they charge first.

Kind regards and best wishes
Phillip

[rkawakami]

Phillip,

I haven't actually seen the GPU chip on the T4x systems with my own eyes, but from my understanding the chip is packaged in what is called BGA (ball grid array). There are tiny solder balls on the bottom of the package which is what is keeping the chip on the motherboard. You are correct in thinking that there is no way for a normal solder reflow machine to attach this kind of component. What is used during the assembly process is a hot-air or infrared (I think) heat chamber. The entire board is heated up and the solder melts enough to attach the components onto the motherboard (in principle, anyway). I don't know about trying to heat the back side of the motherboard (from the GPU) in order to get the solder to reflow. That would probably cause more damage since there are traces running though the board on several layers. The use of lead-free solder and circuit board/chassis flexing is thought to cause most of the disconnect problems.

[phillip]

Hi Ray,

Yes, that makes sense in the respect of having some kind of induction heating to fix the GPU in place and I didn't really like the idea of applying heat to the back of the board for the very reason that you suggest. I don't know how many track layers there are on the system board but there must be a few and I didn't want to have them affected by the heat.

The BGA seems to me to be a poorly thought out way to attach the GPU in consideration of how much the system board flexes and with that little amount of frangible solder holding the connection array together then it seems inevitable that something is going to fail. From what I've seen on the net this seems to be a very common problem with the T4* series which is a pity as it's such a good machine in so many other respects.

Thanks again for your help
Kind regards and best wishes
Phillip