Might try infamous oven trick or heat gun on dead motherboard

Discussion in 'Mobile Computing' started by duronboy, Jan 24, 2019.

  1. duronboy

    duronboy [H]Lite

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    Have an HP DV7 laptop with no video output. None. Not a dead backlight. It's simply not POSTing. From what I've read, the GPU on this particular motherboard(and many like it) simply gets too hot due to inadequate cooling, and possibly poor manufacturing of the GPU chip, itself. It's believable in this case that the cooling sucks because the cooling "solution" for both the CPU and GPU is so light I feel like I could flick the entire HSF assembly across the room with my pinky. To add to that, the coldplate or evaporator for the CPU(A8 3500M) has two heatpipes and is much larger than the GPU(HD 6750M) plate which has a single heatpipe. Also, the GPU plate is single piece, whereas the CPU has a copper center. From what I've read, both the A8-3500M and 6750M have a 35w TDP. So I assume the GPU could get a hell of a lot hotter. Although the CPU is a lot larger than the GPU, if they're both capable of the same BTUs, I would think the smaller size of the GPU and higher thermal concentration would require something even more sophisticated than the CPU? But what do I know.

    I have two or sort of three options:

    1. buy a new GPU chip for $70

    2. apply heat to just the GPU with a heatgun

    3. put the entire mobo in the oven

    Buying a new GPU doesn't make sense because the cost of the chip and my lack of experience doing that. Also, I'm not sure the chips available are exactly what I need. Some of the numbers on the chip match, some do not. I'm not familiar with AMD labeling schemes to determine if the mismatches are irrelevant. To add more doubt, the seller is saying they're for a macbook. I'm sure I could do more research on this, but the cost of $70 for the chip makes it questionable since the CPU in this is pretty farking slow. This whole endeavor is just a fun experiment. I am encouraged somewhat by the fact that my GPU chip is not brown like the "overheated" one in this ad for a new GPU chip. I realize it could be toast and still look pretty.

    Applying heat with the heatgun directly to the GPU seems like a safe enough idea. I remember watching a louis rossman video where he was explaining why the heating trick is a temporary not actual fix. He said if you heat the chip to 120 to 140C and it works, then you know you have a bad chip that will likely fail again and reflowing the solder wasn't the solution because solder couldn't have melted yet. I suppose if it doesn't work I would disassemble and up the temperature, or go on to putting the whole thing in the oven?

    If I put it in the oven, would I need to remove all this stuff?

    Now if it does work, I'm subject to having to do it again in a few weeks/months, especially if the cooling situation isn't improved. However, I'm optimistic that merely putting coolermaster themal paste in there could help. I know that's not the best, but not the worst, either. I'm also not against converting this into a shiatty desktop and massively upgrading the cooler.

    Worst case I part it out. I can probably find something neat to do with the 18650 cells. Mega flashlight or something.

    Going to bed now, I'll try the heatgun thing tomorrow and see what happens.
     
  2. mbakalski

    mbakalski n00b

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    Oct 9, 2013
    Somewhat related, but I just revived a boot-loop bricked Nexus 5x using a head gun.

    It was my first time doing it and I probably should have been more careful, but the phone works now and I was able to get the data off of it without issues. The video I watched on how to do it had a heat gun with a narrow nozzle that allowed for more targeted heat-up. My heat gun didn't have that, so the risk of damaging other stuff was higher.

    I did a 2-3 second heat-up and a 1-2sec cool down before pointing the heat gun at it again. Total time was about 30 seconds.

    Perhaps you can cover the area immediately surrounding the GPU with something heat resistant to try and reduce the impact on other components?
     
  3. duronboy

    duronboy [H]Lite

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    My heatgun does have a pack of nozzles, but I'm thinking the whole motherboard was exposed to temps much higher than 120 to 140C at the time of manufacturing. Although, one phone repair video I saw involved covering the microphone while heating up adjacent components because apparently mics are sensitive to heat? If there are any mics on this laptop motherboard, I don't care about them. I think the only mic is up near the webcam above the display.
     
  4. duronboy

    duronboy [H]Lite

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    No change in behavior after heating up the GPU. I used a laser temp thing to measure the GPU Held it to 129 to 150c for about 10 minutes. I suppose I'll try 250 for about a minute or three and see what happens.