Experimenting with a flaky T42

[axur-delmeria]

I was recently given (for free) a T42 (P-M 1.7GHz, Radeon 7500 14.1 XGA) that doesn't display anything when powered up.
Since the previous owner played 3D MMORPGs on it, I figured that the GPU was the culprit.

Having read a bit about the T40 series' GPU woes. I suspected broken solder joints.
I tried heating the GPU with a hair dryer.
To my surprise, it booted, but not for long.
It booted OK twice.
The third time there was some ghosting on the LCD.
After that it went back to the "no display" problem.

I heated it again today, and it ran fine again. It's currently running Parted Magic from a USB flash disk.
I would have loved to type this post on the T42, but alas, its keyboard is missing a few keys and I removed the Intel 2100 wifi card. uptime reports 1 hour so far.

I'm currently typing this post on my Thinkpad X61 beside it.

Now, I'm torn as to whether to try rebuilding/fixing it or just sell it off.
The battery's still good (it lasted more than 1 hour when the laptop was still running perfectly)
The display is OK (no dead pixels, and the backlight is still white, unlike my X61's slightly yellowish hue)

On the other hand, it's only got 512MB RAM, 20GB HDD, the R, semicolon, and the Previous Page keys are gone, and of course the GPU is flaky.


Should I try using a heat gun on the GPU to do DIY reballing?

[RealBlackStuff]

Welcome to the forum.
Your hairdryer is not going to do the trick.
You need a (very expensive) professional system to achieve a working, permanent result.
Alternatively, replace the motherboard, top up the RAM to 2x1GB and put in a larger HD (up to 320GB).
I have some professionally reballed motherboards available, see The Board Room website.
Or sell the machine as-is, part it out, or give it away again...

[burns334]

axur, Realblackstuff is right on, my vote, save it, buy a motherboard, some keys and ram and you'll have a machine you will enjoy. CPU's are out there to up the speed, motherboard $50 ram $40, keys $10, HDD $40 and download the HMM. Well maybe not, you've got $140 in a machine you can buy all day long for $100. Look at this for $100 with free shipping

http://www.ebay.com/itm/IBM-T60-Laptop- ... 2572wt_712

burns

[axur-delmeria]

Thanks guys. Now I'm more inclined to save it.

I'm thinking of attempting a DIY reflow (crazy I know), but then it won't cost me anything if I succeed.

Gotta find me a heat gun then.

If I fail, my next option is upgrading to an R52 board with Intel graphics.
I've got some spare DDR2 SODIMMs so no problem with RAM.

[ajkula66]

You'll need a different CPU and fan for the R52 board as well.

Good luck.

[axur-delmeria]

You'll need a different CPU and fan for the R52 board as well.

I thought the R52 supports 400MHz FSB Pentium M Dothan processors. Am I wrong?

My current fan is the short one, FRU 26R7860. Is it not good enough for an R52 board with Intel GMA 900?


Alternatively, can I get a 14-inch R52 with a broken LCD and attach my T42's 14-inch XGA display?

[ajkula66]

a) It will never run properly without a pin-mod. I don't know whether you want to go that far.

b) R5x boards utilize different fans than T4x ones. Your short fan is a no-go.

c) Yes.

[axur-delmeria]

How about a T43 board with an Intel GPU? Do I still need a different fan and CPU?

[ajkula66]

Yes.

[RealBlackStuff]

The cut-off line is:
T40/T41/t42 and R50/R51 (400MHz CPU and DDR RAM PC2100/PC2700).
After that it's a different generation with T43 and R52 (533MHz CPU and DDR2 RAM PC2-4200/PC2-5300).
All motherboards are interchangeable within the T4x/R5x series.
R5x fans (are thicker) do not fit in T4x cases but v.v. is OK.
All ATI GPU fans will fit and work on Intel GPU boards, but not the other way around (they fit but do NOT work OK).
R50/R51 have different PCMCIA cages, that do not fit on T4x boards and v.v. does not work either.
14.1" and 15" boards all have the same dimensions. In 15" models an interposer/extender/expander strip is added to make up for the extra width.
That's about it.

[axur-delmeria]

Obviously, this rebuild operation is on hold for now.

The Thinkpad lover in me wants to rebuild it (with R51e/R52 parts) no matter what, but another part is saying: "you already have your almost-perfect-for-your-needs X61, why bother with something that's slower, bigger, and heavier?"

[poshgeordie]

Since you're wanting to do a DIY reflow job, you'll need to remove any red, black or orange dots around the chip (there may be none). Remove them by gently heating (a temperature of a lot less than solder melting point is needed) the chip until you can flick them off.

The reason for doing this is the chip needs to be allowed to "float" when the solder balls melt, and these coloured epoxy balls stop this from happening. Also it's very very difficult to remove the bits under the chip which is one reason we reball, but quite often they come off in one piece.

Good luck!

[axur-delmeria]

Since you're wanting to do a DIY reflow job

Nah, I quit on the DIY reflow idea after a while.

I realized that I preferred a rock-solid Thinkpad (as all Thinkpads should be), even if it meant going the R52 i915 route (I have spare 1GB DDR2 RAMs after all).

But as I've already said, it's hard to find a good reason to rebuild it since I already have an X61 that serves my needs. It's nothing more than an irrational desire, a luxury that I can do without.

"But it's a Thinkpad! Tha'ts the only reason you need!" says a small voice in my head.

[axur-delmeria]

This amusing tale moves forward as I've managed to acquire a beat-up R52 with Intel graphics.
I've already transplanted the planar board and tucked the Bluetooth antenna inside the 14-inch lid where it's not supposed to.

The Pentium M 740 (1.73GHz) runs cool when undervolted, 64C max with Prime95.

Six-cell battery is around 75% capacity, gives me more than 2 hours.

For now, I've removed the Intel 2200bg wifi card due to concerns over the longevity of the Intel 82801FBM southbridge chip.

I'm thinking of some sort of heat spreader for both northbridge and southbridge, but I only have aluminum sheet. Is it good enough, or should I look for copper sheet?

[posscakes]

keep your spare parts handy, hopefully these new mobo's will come into fruition at some point in the near future. http://forum.thinkpads.com/viewtopic.php?f=2&t=110787