Tasty Treats–reflowing a laptop motherboard

Reflowing, what on earth are you babbling about?? Spilling coffee on a laptop?

No that would be an article about how coffee is not to blame for my stupidity, I am taking about repairing a defective computer component.

Various computer components have a flaw related to ‘cold’/poor  solder joints that may crack/degrade after many heat/cool cycles, these joints provide electrical connections between electronic components and if these connections degrade there will likely be a failure or partial failure or the component containing the troublesome joint .

Contemporary computer systems generate a lot of heat while in operation and so cause cycles in operational temperature (in 10 years time when the low energy/heat ARM architecture has taken over as the dominant CPU architecture and GPUs are built on 8nm processes this may not be the case).

After a few years of use these degraded joints may show themselves as they did with my beloved Dell Latitude D820, a fantastic magnesium alloy dockable laptop with a beautiful keyboard and 2 hard disks, in this case my graphics card stopped outputting to the inbuilt LCD and produced scrambled graphics when connected to an external VGA display (no, I’m not a Dell salesman I am just trying to justify why I spent the time fixing this thing… apart from curiosity).

The technique detailed in this post can also be used to repair a XBOX 360 that has a bad case of red eye/Red ring of death

DISCLAIMER: this is a recount of my experience if you read this then get inspired to perform a similar operation and mess up then you may need to grow up and admit its your fault as I take no responsibility for your actions and decisions

Ok what is reflowing?

In short reflowing is bringing the temperature of the degraded solder connecting components to a point where it become liquid/flows and then disengaging the source of heat so that the solder can cool slowly and hopefully re-establish the joints.

So will I get a soldering Iron?

No, most components are BGA/surface mounted and although technically may be soldered using an iron you would waste too much time and need to be a master of soldering…. so I am going to suggest a much better approach, using an ambient heat source.

Ambient? what do you mean? mood heating?

I am suggesting putting your components in the oven or using a heatgun/hairdryer to melt the solder.

I tried the hairdryer method and although it worked well with a faulty XBOX 360 is was not so successful with my D820 which has a NVidia chip that has known heat problems which i supposed meant that a higher temperature than what a hairdryer can provide would be required to reliably reflow the D820.

Easy as Preheat, Prepare and Cook

The steps are as follows

  1. Preheat the Oven to 220C
  2. Remove all extraneous components e.g fans, plastics, keyboards, displays and disassemble the problem device
  3. Wrap all non-relevant portions of the component in aluminium foil
  4. Cook the component for 12 minutes or so
  5. Turn off the oven
  6. Turn on air extraction systems and open all windows/vents
  7. Open the oven door
  8. Leave the component to cool to room temperature before removing from the oven
  9. Reassemble the device (in my case the D820)
  10. Turn on and hope for the best

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Preheating the Oven

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A Powered-on faulty laptop

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Disassembling the Laptop

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Preparing the laptop by exposing only the troublesome components

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Powering a now fully working laptop

A month later my D820 is still working, even after burning it in for 2 weeks using a 3d stress test and no this is not my only computer its one of a bajillion but this is the one I wrote my undergrad and postgrad dissertations on and so I’m nostalgic about it and want it to live forever Smile


Comments

  1. Awesome post, I am checking back on a regular to look for fresh news.

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