Bit of a long shot, if you don't know anything about Nexus 7s or can't provide hints on things like system logging on android and how to force-reload drivers/modules, might as well just ignore this thread.
I'm back on my bullshit and working on old tablets. I love these old Nexus 7 devices. The 2012s had that basically irreparable issue with the flash storage incrementally shitting the bed with successive writes, but they BOTH ('12 & '13) have touchscreen problems. And I am dealing with all of them, across a couple of devices.
The issues are like, maybe you have a digitiser that goes completely unresponsive even on boot, or you'll have dead zones, or you have touchscreen functionality that works, but then after using the device for a random length of time, it'll either lock up completely or go intermittent.
Sometimes you'll have it in a locked up state, but it will come alive just enough to register a touch input on the power menu when you want to reboot. Sometimes you won't.
Then there's the phantom touch iteration of the problem. I have one 2012 that's going totally wild with that at the moment.
And there's the double/triple/quintuple registering on touches on the keyboard that you sometimes get making typing a real pain.
I had one yesterday that looked like it had suddenly decided to become completely unresponsive constantly, but came to life once I plugged it into a computer to do ADB stuff.
I have another one that had issues and seemed to have come good, but it's back to failing after a certain amount of time, but sleeping and waking it fixes it as though it were a software issue.
I've done the basic hardware mod of adding some additional foam over the ZIF connector so the backplate provides more pressure on the contacts. This seems to be only a partial solution. Maybe even total cargo cult stuff on the 2013 which uses a different type of cable connection using a proper socket on the end. (hm, on ONE end, I need to dig in and look at the other end.)
I haven't yet worked on shielding mods, which are supposed to help with phantom touches.
I've also been finding old news articles and forum posts from when these were brand new, where people had these problems fresh out of the box and on pre-retail promotional giveaway versions. Many of these articles mention that users were finding major issues using the device while resting it on a desk and using it with one hand, where the issues didn't occur if it was held in both hands.
In any case there's several suggestions that grounding issues were a big part of the problem.
As for this post, my questions:
Does anyone have arcane knowledge about these devices? About, say, cable decay or ways in which heat from use might cause the thing to behave badly then resolve rapidly when the processor drops frequency due to being slept?
And does anybody know where I would look for system logs that would collect any errors thrown by driver modules during entry into or out of failure states?
Any advice on force-reloading the drivers for the digitizer to see if I could write a script might help unfuck the device when it decides to play dead?
If you've got one of these old devices and it still works well, you might not be aware that ROMs are back on the menu. DivestOS, LineageOS, crDroid, all seem to have very recent builds available with pretty recent security patches applied. I've got one 2013 here running Android 13 at the moment. It's not even as bad as you'd expect. I'm not sure I'll keep it on 13, but it's wild that it works as well as it does at stock clock speeds.