
It was quite an old phone, and not worth very much, but I don't like chucking stuff away if I can help it, so I took it apart and found where the problem was, which was on the main circuit board. So I bought an old phone of the same model with a broken screen off eBay for a tenner, and took the the motherboard out of it. In doing so, I somehow managed to dislodge a capacitor so I I had to solder that back on, but I swapped it in and it worked. Except, even after I rooted it and installed a custom ROM on it, it turned out still to be locked to the last owner's Google account. I spent ages trying to find a way round this, but other than paying for some very dodgy-looking services which would claim to get round this, failed.
In the meantime, my wife offered me an old (though newer than mine) phone of hers, which she'd dropped in the few days between buying it, and a screen protector and case arriving, breaking the screen

Having finally booted it up, it initially refused to connect to the cell network, and then seemed to work intermittently, receiving messages and voicemails eventually, but unable to make or take calls. Otherwise it was working, so while I figured out what to do with it next, I started using it, but decided not to buy a case and screen protector yet, in case I couldn't fix it. You can see where this is going. The following day at work, trying to message a colleague who I was rushing to meet having given the wrong key, with the caseless phone hard to grip, I dropped it face down onto a tiled floor, with forseeable consequences.
So I ordered a used, working copy of my old phone off eBay for £35, which is what I should have done in the first place, before I wasted hours of valuealbe life and about the same amount of money trying and failing to fix two other phones.
Maybe there's a lesson in there somewhere? Chuck stuff away instead of fixing it? Go back to carrier pigeons?