Probably a cracked circuit board somewhere. They can be very hard to find and very tiny. Trace around with a voltmeter and see if you can find where the voltage comes back. If you can’t find it try putting a jumper wire from the good side to the bad side. Get a schematic or wiring diagram, or draw one yourself so you understand what’s what.
My Kodak has the same problem. I think the little relay that unlatches it is just a little off adjustment, so I give it a little help with my fingernail sometimes. Either yours is out of whack due to wear or misalignment (damage?), or just permanently broken.
I doubt you’d be able to find parts for it. Try epoxy for structural repairs or hot glue for just keeping things in place. Use rechargeablesifyou can. If there’s an external charging port, seal the batteries up so it doesn’t fall apart and use it as long as you can.
You’ve had that a long time and I expect that you’ve got it pretty full of data. All I can think of is the memory is full. I have 8 GB on my BLU Dash 10 and I’m always cleaning it out, completely reset it once in a while, and store all the apps and data I can on a micro-SD card. If this isn’t the problem try the factory data reset (under settings-backup&reset) which will wipe everything and you can start over. Get all your data backed up first to your computer.
That short could be hard to find. Here's what I'd do, after checking everything obvious. Find an old headlight bulb ( I always save stuff like that) and hook the high beam (which seldom burns out, the low beams go first) in place of the fuse. Be very careful with the wiring and tape the connections. Drive around and see if the light ever comes on brightly when you hit a bump or something. It may dimly glow when you use the taillights.
It sounds like the lens is jamming. You might have some physical damage, some debris in the gears or mechanism, or it's just worn out. You could try taking it apart and cleaning out the gunk. Good luck, but you will probably end up buying a new, better camera.
Have another PC somewhere that you can swap power supplies with? That will tell you. Intermittents are the worst things to diagnose. It could be something shorting out somewhere, but probably the power supply. I'm an EE and I design power supplies, but I don't fix PC ones. I hate to tell you this, but a 13 year old PC doesn't owe you anything, just sayin'. Get a new motherboard and power supply and stick it in that cool case.
I have a $70 Blu phone and I've run out of space a lot. Our friends at Google like to push updates on me, and there's a bunch of crapware that I never use but can't delete. I presume you've gone to the Settings--> Device--> Storage -->set the default storage to the SD card. You can also try going to settings--> Device-->Apps and go through each app. Some have a button to move to the SD card. Disable ones you don't use, uninstall them if you can, clear the cache (some say "manage space"). The next step is to uninstall updates. Sometimes you will get a lot of space back. They seem to keep all the old updates just in case you want to use them ....? Anyway, the next thing to do is reset your phone completely. You can probably get back half your internal storage, because that's what it came with. Google will immediately start filling it up again, but at least you're starting fresh. Kind of drastic, because you'll have to fiddle with it to get back to the way you like it.
If it has the original battery, you might want to consider a new one. After 12 years it doesn't owe you anything. You can have it tested, usually for free, at many parts stores. They will put a load on it and see if it has the current capacity. You should also put a voltmeter on it and see if you get 12.8 volts or so when the car is running. If not, your alternator needs work. If you have a newer battery and the alternator is putting out, you probably have something loading it down. Disconnect the terminal and put an ammeter in the line, and see what it is (with the engine off).
A lot of gadgets have snap-in cabinets, because they're cheap and easy to assemble, and stay together pretty well. Get a thin screwdriver and pry around until you locate where they are. You might find a fuse inside, or a fusible resistor. That doesn't mean that when you replace it, it will work again, but it's worth a try. I sometimes use an incandescent bulb in series with the AC line to try things that might be shorted out. If it is, the light will light up and protect yet another fuse.