Wednesday, February 16, 2011

Dell XPS No Video (2)

This is unit #2
Dark Blue cover
This unit arrives with a request for DC Jack repair.
the jack repaired and unit plugged in to test and shuts off immediately.  So I had to inspect inside.


Opening the unit to get to the GPU portion to begin diagnosis or repair. Because you have to remove the heatsink before the motherboard, and after removing it what I see is the 'Worst Case' scenario of how a GPU should look.  


In an effort to get video working someone put balls of solder under the heatsink to apply pressure on the manufacturers solderballs under the GPU making contact with the motherboard. Along with way too much thermal compound. Though the idea was good in principle material used does more damage. The solder not only contacted/shorted resistors and jumpers on the top of the GPU but removed a number of them (probably inside a ball of solder).  Those extra small resistors and jumper sets, clock speed and memory size information for nVidia. 
But the unit was said to have worked!?  Or so I thought.


The root cause of most XPS having no video and (using the nVidia chip) is contact oxidation. One or both, motherboard or GPU. Since the number of various manufacturers use this video chip, my guess would point to the GPU.  Could it be the time it takes from nVidia to the computer factories allow for oxidation to develop on chips not shipped in Nitrogen sealed packages to save a few dollars?


I have seen the same issue with Gateway, Dell, HP and others.


Also appears to have a dead short between layers of the motherboard.  Usually caused by forcing upside down harddrive into slot or screw or another part inside laptop.


DIAGNOSIS: Not Repairable



8 comments:

  1. My word, what a mess! Infuriating to see how some people can so utterly destroy a MB.

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  2. pour ce probleme je peu le resoudre en coupant un peu de la partie presser

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  3. "DIAGNOSIS: Not Repairable"
    I love it.

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  4. "Not economic to repair" is a common expression around here. :-)

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  5. Jack: Il ne peut pas être réparé. Le GPU exigerait reballing ou remplacement. L'autre option est remplacent la carte mère.

    Larry/MattBrad: Agreed. Cost and Time is too great to even attempt.

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  6. Mayo:one technicion said me that what they do,if they got garbage characters on laptop screen then they change that small resistors/capcitors upon the GPU one by one and solve that problem of garage characters on screen.what you say about this?

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  7. Asifnawaz: That may solve the problem but the problem is the addressing of the memory lines, not in voltage or current levels. Binary is 0 & 1.

    When the binary addresses are incomplete, you get incorrect characters. If that works for them, thats good. I never try to offend other techs method that work. But if you spend 3 hours replacing one resistor at a time, thats not productive. The way I did it fixed the problem in 20 minutes.

    Good Luck to them!

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  8. hi mayo aim very interested in your posts am a technician and I love electronics since I was a kid its my hobby I would like to ask you about the Toshiba A305 power problem when it work on the battery but not on the dc-in iv tested all the mosfets and capacitors I thought its a problem in the quad ic ,that is in the power unit in front of the white fuse ,is that true ? or did you face this problem before? This is also a common
    problem in the dv9000 and dv6000 Intel versions I also tested the a/o4407 and the FDS6679 and also changed the max8734 and the max8743 and the result still the same no dc in power plz mayo will you help me in this ,on these models ( hp dv9000 /Toshiba a305) thanks our leader ..regards

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I cannot repair laptops for you via the internet, I can only answer questions related to posts. This is because I have not had experience on every motherboard that is out there. Bear with me.

If you do need it repaired. Contact me for quote (US/CDN Only)

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