[General] How can I fully drain every scrap of power from my phone?

[General] How can I fully drain every scrap of power from my phone?

More of a general question for all phones.

I have an OG Google Pixel 1 that one day randomly hard bricked itself. Shows up as QUSB_BULK in device manager.

The phone is in an extremely low level Qualcomm mode. This can be caused by:

- Actual physical hardware issue (will likely never get past this) such as memory dying

- A bad software update (known issue for some Pixel updates)

- Random

It's possible it could be either of the last two reasons - so you can attempt to reboot out of this low level mode.

However, the only way to do so is to drain the power completely and I mean COMPLETELY - so NO reserve/backup/emergency power - every single SCRAP has to be removed.

This can be done by disconnecting the battery, however you have to go through the screen to disassemble the phone to get to it - high risk of breakage.

Thus, I want to try and achieve this without disassembling the phone.

- My phone bricked in August 2020. It was charged a bit just after this event.

- It was never charged from then until I think about a year later (2021), when I charged it for around 20 minutes to try to revive it.

- Since then, the phone has not been charged (currently it is October 2022)

- Holding down the power button or any button combo shows no sign of life.

- Also, I've tried every combination of holding buttons (Power/Volume Up & Down, for varying lengths of time 1s to 10mins)

I heard that assuming the battery is fully discharged, I can ensure there is no reserve power by holding the power button for 10 seconds.

1. Is that actually true - will this eliminate all power from the battery and thus board?

2. If not, how can I achieve this?

I want to be absolutely sure that I have done all the right steps in removing all power from the board and battery, without actually disconnecting the battery itself, considering that it hasn't been charged in a year, before I try again now in October 2022 to revive it again.

All help appreciated.