I’m quite fond of buying things used and then fixing them up. My current smartphone, and iPhone 5s, was purchased second hand from the United States and I’ve already replaced the battery once. Lithium-ion batteries have a limited amount of charging cycles and my replacement battery was also nearing the end of it’s life.
I ordered a replacement battery from eBay and after receiving it I went about installing it. I’ve replaced various smartphone batteries over the years and it seems I had grown complacent. I had lost the respect needed to complete the delicate task.
While rummaging around the innards of my phone I inadvertently dislodged a surface mounted component called an inductor. As luck would have it this little component was critical to the operation of the phone. I later learned that it forms part of the battery monitoring circuit that the phone uses to detect the battery status. Without this ability the phone turns on and as soon as it checks the battery it reboots, mistakenly thinking that the battery is missing. A phone that restarts every 3 minutes isn’t very useful.
Luckily I’ve dealt with a few inductors during my stint at University and I was able to diagnose the problem, find a replacement component from a broken phone in my parts box. Then I ran into a problem. The inductor was an 0402 (Metric) or 01005 (Imperial) component. This means that it is 0.4mm x 0.2mm across. That is about the size of the period at the end of this sentence.
I have some experience with soldering surface mounted components but nothing on this level. I know when to tag out and get help. I then proceeded to look for a phone repair shop that could do board level repair. Thankfully I found a small store in the city where a friendly technician was able to fix my phone in under an hour for $80. I was happy to pay him for using a skill that I don’t have.
My phone is happily sensing the battery again, I’ve installed the new battery and I’m grateful that there are people who are vigilantly fighting the fight against planned obsolesce.
Special thanks to: