ChaoticNeutralCzech

They are also used as parking ticket machines (in Europe we don’t have parking meters, you buy a ticket and display it on the dashboard, or in some places get a virtual ticket for your license plate). I don’t think the company exports these outside the Czech Republic, and Euro coins are not magnetic. So I’m afraid you’ll have to find another magnet-related exploit (maybe this)?

Here is a datasheet of one / photo. I don’t have the video of me fishing coins, I probably deleted it because it was unwatchable (it’s hard to fish coins while filming covertly!) but about 5 coins fit into the space behind the keyhole before they start being visible. The front panel is non-magnetic, unlike CZK coins, and the sound of fishing them out is very similar to throwing them in, so there is little suspicion unless you are at the wrong-gender toilet. Unfortunately, 10 CZK coins take effort to jam into the slot, so almost only coins up to 5 CZK ($0.25) get accidentally thrown in. Still, pays for my bus home.

A common public toilet till machine has a keyhole that looks like a coin slot. Turns out, HDD magnets are the perfect shape to fish out any coins mistakenly thrown in there.

Sensor wear

This does not happen AFAIK. Most phones have no shutters so tge sensors receive light all the time, and the little required power does not overheat it.

mechanical parts (if any)

This is a valid point but the actuators in a phone camera’s focusing mechanism are more like a speaker than a motor. They can last for ages, and many apps allow disabling autofocus when idle.

heat

This one is valid. Even basic image processing is a load on the CPU, and recording/streaming definitely is. Depends on how the camera is mounted to allow airflow.

gamble and see how long it lasts

Sure. The stakes are not very high if the phone would otherwise lay in a drawer.

I don’t know (as in I have zero clue) the camera is designed to operate that way.

There is no reason a camera cannot be on all the time other than power consumption. Why couldn’t it? The only limitation is software. Other parts of a phone can overheat from continuous operation (CPU et al., voltage converters, maybe flash LED and vibration motor) but not the camera.

The camera is on all the time, the recording/streaming only starts when requested or on motion detection. Did you expect a PIR sensor on a phone?

This is the most likely failed part, yes. If you feel adventurous, you can try repairing it like DiodeGoneWild. Looks like the auxiliary power supply (5V 1A independent of others; powers BIOS chips in standby to allow soft power-on) works but the main one does not. Unplug the connectors, connect the black (GND) and green (ENABLE) wires to signal a POWER ON state and check all the voltage rails. Many units use a powerful 12V supply and step-down converters to create the 5V and 3.3V rails, as well as an inverter for the -12V one – if that’s the case, you can try backfeeding 12 V from another PSU and see if the rest come on. Once you identify the failed power supply, check its primary transistor(s) (big 3-pin components on a heatsink) for a short or open circuit.

Yeah, you can run a SATA & power extender cable (or reroute the existing one unless it’s just a connector soldered to the MoBo) out of the bay and affix a 3.5" drive elsewhere in the box or outside of it.

make titles serif only

I don’t want to question your aesthetic choices but I think it hurts readability.