My mom and dad had two old HTC Desire 510 phone sitting in a drawer and asked me to help them erase their personal information and recycle the devices.

One device works without issue and erasing was a breeze.

The other, however, seems to be completely dead, however. What I know:

1. No matter how long it stays plugged into any number of chargers (OEM and non-OEM), the screen never comes on, nor do any LEDs flash, etc.
2. The battery is not the issue (the battery from the dead works in the other, working phone, though the battery from the working phone doesn't work in the dead phone).
3. The liquid sensors do not appear to have been activated.
4. Holding down the power and volume down buttons for 2+ minutes does nothing, whether the phone is plugged in or not during the process.
5. Cleaning the battery contacts on the battery AND the phone does not resolve any of the aforementioned issue.

Anyway, I'm less interested in getting the phone working than I am in understanding what would be left to possibly test/troubleshoot. It doesn't seem like the display, since neither the LED flashes, nor does the speaker make any audible sounds. I'm, then, assuming that the issue is the logic/motherboard, but would love some expert advice since this is outside the realm of my expertise.

Assuming it's dead, any suggestions on how to safely and responsibly recycle or dispose of a phone that won't power on and which may contain general personal information would be greatly appreciated. Although, truth be told, I cannot imagine who would want to go through the effort of unsoldering the storage chip and porting it to a different board just to get access to my mom's recipes and sewing newsletters.

 

Thanks! That's, more or less, what I was guessing. Thank you for the confirmation.