Old devices refusing to be repurposed

(Originally posted on the RetroMat site in May 25, but sits better here). 

Buoyed by the successful rescue of an old Android phone (see below), I've just tried some other old devices that were lying in my electronic junk box, but unfortunately, for different reasons, I was unsuccessful:

•  Another Moto smart phone, different model, that simply fails to power on when connected to a power supply. Plug and phone get vaguely warm and when disconnected, there's a brief flash from the light at the front. Cause: battery failure.
•  An HTC Desire phone from around 2010. It starts promisingly: the battery gets charged, the phone powers up and displays a logo and vibrates and buzzes loudly, but the screen goes blank after a while. Sometimes it comes back on and the buzzing is repeated insistently, but it won't  go beyond that initial screen. Suspecting the removable battery could be at fault, I've checked it with a multimeter, but the voltage was pretty close to the specified value. I've been able to get to the Android menu by pressing and holding volume down and then the power button. I've then tried a few of the options there, such as erasing data, selecting the 'rescue' (reset?) option and even 'fastboot', whatever that is, but all to no avail. Back it goes into that box! Cause: hardware failure of some type.
• A Hipstreet W7 tablet. IIRC, this came free with a phone contract many years ago. No-one found it remotely useful at the time, so it was consigned to the box of unwanted devices soon after. Perhaps it could find some use at last as a media player? When plugged in, after some time, it starts up and displays a family member's name and a password prompt. There's a reset button, but all that does is restart the tablet, not reset it to factory settings. It seems, in order to rescue the device, it needs to be booted up with a previously-created rescue 'disc' in the usb port. Needless to say, there isn't one. Unfortunately, but not unsurprisingly, said family member doesn't recall the password after all this time. Cause: security policy.
• A 4 GB Sony Walkman (NWZ-A816) from around 2008. It was used often until I had my first smart phone a few years later. The battery had started to expand a while ago, so it was removed and disposed of at the recycling centre. It still powers up, though, if plugged into a power supply by USB cable. It can even be made to continue to function as a media player (music, photos, videos).  What it steadfastly refuses to do, however, is to reliably accept files that I try to transfer to it from my laptop - I keep getting message libmtp error: could not send object. IIRC, I had a similar message when trying to send files directly to the Moto G rather than to a MicroSD card mounted locally on my laptop. It's quite possible that the problem arises from the file transfer protocol as implemented in my laptop's OS (Linux Mint). However, given the limited usefulness of the device (small capacity, no battery, no support for flac files!), it's probably not worth pursuing further. Cause: incompatible standards?