Nexus 7 headphone jack fix
I have a first generation (model year 2012) Nexus 7 tablet. Nowadays I mostly use it to watch movies during my daily commute. About half a year ago I noticed that one side of the headphone output does not work. After a reboot and plugging the headphone in and out several times it started working most of the times. Then stopped working completely.
I started searching the internet and found a solution: if I hold the tablet in landscape orientation and start twisting it (pull the left top forward and push the right top backwards - or in the other way around) it works. But it's very inconvenient to hold it twisted and I was a bit worried to twist the display panel. I also found this link which says that something at the speakers wears down and gots short circuited. I was a bit sceptic because it appeared to be some kind of contact problem to me but I gave it a try. It didn't work. Of course.
This week I had enough of twisting and disassemled the tablet again (which is surprisingly easy by the way) and took a look inside to check what's moving when I twist it. And finally found it! There is a flat ribbon cable under the battery that goes to the speakers, the headphone jack and the USB connectors. This cable was moved by the battery during twisting. I pushed at the connector part of the cable (which is under some kind of electrical tape) and it started working immedately! And works since then too. After that I pulled up the tape to check what's under it: just a regular latch-type ribbon cable connector. Here it is:
It works flawlessly since then.