Author Topic: BGA reflow to fix GPU  (Read 2384 times)

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Offline microbug

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BGA reflow to fix GPU
« on: June 08, 2016, 08:35:04 pm »
I've bought a couple of cheap dead GPUs from eBay to try to repair. I have an Atten 858D heat gun, a Brymen BM257 multimeter with a thermocouple and some cheap chinese flux paste (tested it for continuity and it's non-conductive). Just wanted to check if there's anything I should know before I attempt this. My plan is as follows:

  • Cut an appropriately-sized square from a piece of aluminium foil to shield the rest of the PCB.
  • Apply flux paste around the outside of the GPU chip.
  • Set fan speed to low and gradually heat the GPU up to 220 celsius (using thermocouple to check temperature).
  • Hold at 220 celsius for 15 seconds
  • Allow to cool for 30 minutes.

If anything falls off I can resolder with my Hakko FX-888D.

Am I missing anything? I'm planning to set the temperature with the thermocouple on the chip rather than the 858D's slightly dodgy temperature setting (thermocouple said it was 250 degrees when it was 220 on the display).

Also, should I get a cheap IR thermometer instead of the thermocouple or will it do?

Thanks in advance
« Last Edit: June 08, 2016, 08:36:48 pm by microbug »
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Online wraper

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Re: BGA reflow to fix GPU
« Reply #1 on: June 09, 2016, 01:05:51 am »
 :palm: once again someone clueless tries to do this kind of BS. First of all those chips themselves are faulty not soldering. By heating them, you can revive them for some short time but this is not permanent fix. Secondly good luck melting solder balls under such big BGA whith such hot air station. Probably you will heat up the thermocouple by blowing hot air on it, but not solder underneath of the chip.
 

Offline crispy_tofu

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Re: BGA reflow to fix GPU
« Reply #2 on: June 09, 2016, 01:07:24 am »
Obligatory link to a Louis Rossmann video: :)

 

Offline microbug

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Re: BGA reflow to fix GPU
« Reply #3 on: June 09, 2016, 06:54:16 am »
Watched the video. That sucks, guess I'll flip the gpus as broken.
It's not your beliefs that make you a better person, it's your behaviour. — Greywoolfe  •  microbug.uk (not yet complete)

Just because I have lots of posts, doesn't mean I'm any good at this!
 


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