Fix-A-Brick 2: Nexus 5X Rises From the Ashes

It was but two weeks ago when I told my story of woe —  the tale of an LG Nexus 5X that fell ill, seemingly due to a manufacturing fault at birth. I managed to disassemble it and made my way through a semi-successful attempt at repair, relying on a freezer and hairdryer to coax it back to life long enough to backup my data. Try as I might, however, I simply couldn’t get the phone running for more than ten minutes at a time.

All was not in vain, however! I was rewarded for documenting my struggles with the vast experience and knowledge of the wider Internet: “Hairdryers don’t get as hot as heatguns!”

It turned out I had just assumed that two similar devices, both relying on a hot bit of metal and a fan as their primary components, must be virtually identical if rated at a similar power draw. I was wrong! Apparently the average hairdryer stays well cooler than 150 degrees Celsius to avoid melting one’s silky locks or burning the skin. I even learned that apparently, wet hair melts at a lower temperature than dry hair. Who knew?

Armed with this knowledge, I rushed out and bought the cheapest heat gun I could find — around $50. Rated up to 600 degrees C, this was definitely going to be hotter than the hairdryer. With the prevailing opinion being that I had not applied enough heat in general, I decided to also increase the heating period to 90 seconds, up from a quick 30 second pass originally.

After a quick disassembly of the phone, I was ready to go again. With the motherboard pinned down between some books to stop it skating around my desk from the airflow, I aimed the air primarily at the biggest chips on the board, being sure to move it around to avoid overheating any one spot and dislodging parts.

Lo and behold, it worked! The phone fired straight up, with a clean boot. Even though I’d had the phone previously fail in the middle of an update, there were no problems at all. I was able to fire up Google Photos and set it to back up the last of my photos to the cloud, and left the phone to do its work.

Welcome Back a Dead Nexus 5X

Over two weeks have now passed, and I am happy to report the phone is still fully functional. While I no longer use the phone day to day, it has survived occasional web browsing as well as a stress test of quickly taking 17 photos with HDR enabled to see if putting a load on the processor would cause the problems to reappear. The mechanism of this repair still isn’t 100% clear to me — is the hot air gun causing the BGA solder balls to reflow, or is it some other kind of thermally-related witchcraft? Pontificate on this in the comments. To me, it feels like solder rework. Admittedly I’m not using best practices for hot air rework. Bil Herd has a guide for SMD desoldering without damage to components. His techniques can easily be adapted for reflow without removing the part from the board. A better method would be to remove and reball the BGA chip, but that is beyond my current capabilities.

It was a pretty rewarding fix in the end. It’s a good feeling to have a working phone at the end of it, rather than sending more electronics straight to landfill. Of course, my unreserved thanks go out to the Hackaday and Youtube commenters who pointed me towards the light… or in this case, heat.

Read more from this series:
nexus 5x

40 thoughts on “Fix-A-Brick 2: Nexus 5X Rises From the Ashes

  1. Yah, sounds like you reflowed it…. But… done dry it tends to have a 3 month lifespan…. use flux and it can go a year to permanent….. full reball is the most reliable, but harder.

    1. I used to use the same method with graphics cards and I agree about the roughly 3 month time thing. That was a GPU that got really hot lets hope this was something that doesn’t get quite as hot and maybe lasts longer. If this was my phone to help reduce thermal stress I wouldn’t use it very much during charging as I think the added heat from charging may have put whatever component over the edge.

    1. Quite interesting / News to me / Sounds legit.
      At ~4:27 he talks about evidence but i can’t find it. No links in the description (or i couldn’t find them between all the ‘unrelated’ links), no hints, no nothing…

    2. If you watch more than one of these videos, you’ll understand the bigger picture. He says that reballing is not a catch-all. There are usually underlying problems that can sometimes be resolved temporarily by reballing or replacing the chip in question. However if the original problem was a short in the solder under the chip, removing that short by reballing would remove the short. He’s right and you’re applying the knowledge wrong.

    3. An interesting take, but without a real failure analysis or explanation of how reballing processing puts the chip back into service besides remaking board connection, if only for a short time, I am unconvinced of the general argument. Detecting ball failure usually requires X-ray inspection. Referring to the other components on the carrier as ‘bumps’ cuts into the argument that he knows what he’s talking about beyond individual experience. For certain, heating doesn’t reset any magic timer that he claims Apple has built in.

      The mechanism I’ve seen for such things is metal fatigue from thermal cycling and differential thermal expansion because one item is heated and the structure it’s attached to is not or the items are of dissimilar thermal expansion characteristics. He didn’t say if the 120C applied temp restored function post heating, but as thermally induced fatigue cracks increase in size they can be closed by restoring the operating temps to close them again, far below the melting point of the solder.

      One thing I believe can happen is a failed connection causing a critical regulation function to fail which cascades to physical damage on the chip. Obviously repairing the connection won’t repair the damage done so it isn’t a cure-all.

      His particular experience with particular hardware suggests the latter may be the case, but I doubt it has to do with the ‘bumps’ or a secret timer and may have more to do with higher temperature excursions from Apple not using forced dust/air cooling. If it is thermal then it would be interesting to have an app that kept count of those cycles.

    1. And for anybody complaining about Harbor Freight materials being junk, there is not much to balls up on a heat gun. Even the Chinese can manage to build one decent enough for not much at all. It’s a fan with a heater coil and possibly something to switch the fan to 2 or 3 different speeds. The cheapest one will work, unless you are going to be running it for literally hours on end every day.

      1. I do indeed have a harbor freight heat gun that they munged up the assembly of–it will sit there and run wisps of smoke, with the aroma of burning plastic emanating as well. I’ve never been bothered to pull it apart to find out what’s going on–I just unplug it when I’m not using it.

    2. Yeah tried the $10 Drillmater from HF and it died a few mins into working with it. Decided to go with a Stanley for $30-40 and no more probs. Did the same reflowing trick on a $20 dead PS3 slim (flux used) . It has been running Gran Tourisno 6 reliably now for 3 months along with all types of video streaming apps. Awesome to see it works on some phone issues too.

  2. My phone bricked cuz I ran out of battery before being able to check the option to charge the phone rather than using the USB to transfer files or charge other devices so as of now I have a blinking red light with a Nexus 5x with the pretty blue back color… What a dumb thing to do when you plug in your phone it doesn’t charge and then you have to choose the option to charge your phone or to transfer files it should be you plug in your phone then go to the options screen to do it but instead from the update it seems this bug has caused me to lose $300 thank you very much Google for robbing me

    1. After a hard shutdown from running out of power the phone will default to charging mode (because it is the only mode) when the phone is plugged in completely shut off. You should see the LCD screen light up within a few minutes once the battery comes out of its under voltage protection and the screen should show the battery charging icon.

    2. The USB mode is definitely not the problem here.

      The phone will (well, should) still charge even if you select “Transfer files” mode – the selection is a computer security feature, not a “disable the charge controller” feature.

      Do you have another charger and/or cable you can try?

  3. I actually used a piece of paper folded, and wedged it under the heat shield(?) (where the fingerprint scanner is located), then screwed the thing back on, put the case on and it’s been a week with no problems! Well I lost the fingerprint scanner (it’s my dad’s phone so not that big a deal) but it saves us on buying another phone :D

    Definitely a working method. If freezing your phone revives it – this will work better I believe!

    Obviously heat gun is the best way to go but I don’t have one and didn’t wanna take the risk :l

    Hope this helps!

  4. My Nexus 5x bootlooped endlessly about 3 weeks ago. Bought it from the Google Play store Dec of 2015. Even though it was out of warranty by a few months, they replaced it with a refurb.

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