[General Questions and Answers] NimbleWeasel:
continuation

6. LET'S GET SERIOUS!

If you are reading this, you either didn't read or you decided not to follow my most obvious advice in section 5. So be it. If you want to carry on from here, be sure to re-read my disclaimer at the top of my post.

There are 3 DIY possible fixes for the WiFi problem - none is guaranteed. I will describe them from the most harmless to the most kamikaze/deadliest. All of them will require you to open your device; if you are not careful and damage any of the components inside, you will end up with a worse device than before - but hey, don't say I didn't warn you.

At this point we assume that the cause of the problem is a faulty solder joint of your WiFi IC. The goal is to try to restore that solder joint. To do that, you will have to:

I. Open your device

II. Find your main board and separate it from all connected plugs

III. Find / identify the WiFi IC chip on the main board. I recommend searching for a service manual for your device, or/and searching for a disassembly video for your device; you need to know which one of the chips on the main board is the WiFi one.

Once you have identified your WiFi chip, you have 3 options, which you may combine with each other, but I recommend to try them out one-by-one as follows:

6.a Sellotape / Scotch tape

You need to make sure that your WiFi chip is pressed against the main board (ideally, this ensures the broken contacts touch each other, solving the problem). The best way to achieve this, is to attach a series of tape strips on the top of the WiFi chip, causing it to be pressed against the main board by the surrounding cover/hull once you reassemble/close the device. The tape strips are just a suggestion, do whatever you find convenient as long as you ensure that the chip is pushed against the board at all times.

This method may solve the WiFi problem already. When you turn your device back on, give it some time (5-10 minutes) and reboot it a few times if the problem still persists. My own WiFi didn't function right away, but after a while it finally recovered - hurray!

6.b Refrigerator / Freezer

Instead of using the tape as described in 6.a, you may first try to put your motherboard in a fridge for a few hours/days. But make sure to put it there in a plastic bag, and avoid moisture as much as you can, specially when taking it out of the fridge. Make sure its completely dry before reassembling your device!

By the way, try the refrigerator option BEFORE you try the freezer option!

6.c Oven

If everything else fails, the oven might be your last chance. This is not a joke, but as you probably can assume, it is "All-In" i.e. highly risky. The theory behind this is that high temperature will cause defective solder joints to reflow, reconnecting and thus fixing the problem.

You should only try this as a matter of last ressort. Be warned that you may fully destroy your main board, and there is a high chance that you will. Also, you may cause serious injury to yourself or others. Make sure you make backups of your data first. DO NOT BAKE THE WHOLE DEVICE, ONLY THE MAIN BOARD. DO NOT BAKE THE BATTERY!!

If you are still reading:

I. pre-heat your oven to 385° Fahrenheit (196° Celsius)

II. put your main board in the oven, bake it there for 7 minutes

III. remove from the oven, let it cool down until every component of the board has room temperature

Finally, here is a video of a guy doing a similar thing, but with a heat gun:

h ttps://w ww.youtube.com/watch?v=A4n0j3uaS7E

Ok, this is all, I hope I could help you.

Good luck!