Lewis' Blog Tales from the trenches of information technology

21Nov/103

The strangest laptop repair I’ve ever done

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Those of you unfortunate enough to have purchased notebooks (and video cards) with so-called "high performance" video in recent years with some Nvidia (and other manufacturers', I would guess) chips have my deepest sympathy. We spend (spent) a good deal of money for the "upgraded" video, only to find that truly, the light that burns twice as bright burns half as long, and typically, just outside of the 3-year warranty (in the case of the ThinkPad T-series), we get not only a BSOD, but garbled output on an external display, as well.

Nvidia's problem has been quite well documented on the net (for examples, see here and here and here).

Well, my wife's T61 was no exception, and about a month out of warranty, sure enough, after some fanfare (intermittent BSOD, hangs, etc.), it finally went black (well, mostly). Connecting to an external display proved that the system was indeed running, but that the video was unreadable.

I considered attempting to purchase warranty service after the fact, as recommended by the Lenovo rep quoted in the third link, above, but after reading more in that particular thread, I decided to try reflowing the solder myself.

It took me about an hour to strip down the machine to pull the system board (hint: if you do this, be sure that you take your time, and prepare for the reassembly of the machine, particularly insofar as keeping your removed hardware in order and obtaining a supply of thermal grease for the reinstallation of the heatsink & fan assembly). I noted that the board fit perfectly in our Black & Decker toaster oven, so I pre-heated the oven to ~385℉, fashioned three support "balls" of aluminum foil (each approximately 1" in diameter), and placed the board face up on the supports. When the oven was at temp, I put the board in for about 7 minutes.

Remember that the burning point of paper is 451℉ (like Ray Bradbury's book!), so the labels didn't even singe. I did not remove any of the plastics on the board (the insulation sheets), nor did I remove the VGA connector (which has a plastic insert).

Contrary to all of the warnings by the aforementioned Lenovo employee (Mark) in the forum, I had no trouble with this procedure (hey, the warranty was up, anyway; a new system board for this model runs about $600 from IBM/Lenovo - yes, some have reported factory repair quotations of less than this; I suspect that those repairs only include properly reflowing the solder for the GPU, and not a complete board replacement). The board shows no sign of being subjected to any heat beyond the normal range one would expect after 3 years of continuous use. I did not shield any parts of the board with aluminum foil, as some youtube videos seem to indicate is necessary when using a heat gun for the procedure (I figured it would be better to evenly heat the board in an oven, than to blow hot air on it "in a circular motion," subject to the ambient temperature).

After an hour to cool down, I began reassembling the machine. This procedure took me about two hours; I cleaned as I went. After that, I had to scare up a power supply (I had a replacement unit in stock which didn't seem to be working; however, upon re-seating the battery, I found that the adapter did actually apply power to the notebook). I pressed the power button, and almost fell out of my chair (up to this point, I pretty much gave the whole thing about a 50/50 chance of success). The screen was bright & beautiful, with no sign of its previous trouble.

How long will it last? Who knows! Could I offer this as a service to my clients? Absolutely not. The risk of failure, I suspect, is not worth the time and effort to try (I don't mind wasting 3 hours on my own junk, but spending 3 hours on someone else's, with no result, either yields an unhappy customer or an unhappy me).

Anyway, if you're seeing similar issues with your ThinkPad T4x-series or T6x-series machine, and you're out of warranty with a few hours to kill on a Sunday afternoon, at least you know that it worked for me. 😉

Comments (3) Trackbacks (0)
  1. The above procedure worked fine for a couple of weeks, and then we returned to the black screen. This was not unexpected; perhaps I didn’t bake it long enough. Anyway, I tore the machine down again today (4/24/2011) and re-baked the board at 385℉ for 10 minutes this time. Reassembly went fine, and the screen came right back to life. We’ll see how long it goes this time around.

    Anyway, just wanted to keep everyone up to speed. 😉

  2. Hey 2014 here and after about seven years, my friends Lenovo T61p also had the same symptoms. After following your instructions, it works again. 
    It felt rather adventures to bake my motherboard.

    Just wanted to say thank you for your tutorial. I'm rather surprised though, that the condensators and chips are still working. Thought they had a lower temperature limitation.


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