Asus Chromebook Flip C436FA: cannot boot normally with the battery disconnected

Support
1

Write protection is enabled. According to the documentation I was able to find, this device is a CR50 device that needs to have the battery disconnected in order to bypass the write protection. I’ve disconnected the battery, but for the life of me, I cannot boot it to flash the firmware.

If I press the power button, nothing happens.

I noticed that the red charging light is flashing.

I’ve also noticed that the power light (on the power button) also sometimes flash. If it does not flash, I can disconnect the power from the chromebook and reconnect and then it will flash.

If the power light is flashing, and I press the power button and the ESC key together, I can get it to boot into recovery mode. I’ve run one recovery to completion, but after I removed the USB stick, it powered down and did not boot normally.

I’ve tried hitting the Refresh key while pressing the power button. Nothing.

I’ve noticed some people asking on Reddit but they never got an answer.

2

one of:

  • USB-PD charger failing to negotiate sufficient power to boot
  • EC firmware not persisting PD-connection when switching to RW firmware, and no battery to buffer

if it’s #1, then a different charger might work. If #2, then nothing you can do other than use a SuzyQ cable to disable WP.

3

Apparently, there’s a third option: simulate a live battery failure. It is risky… but that’s a risk I might want to take. I’ve tried two different models of chargers with the Chromebook. No dice. These are rated for well over what the Chromebook needs. (Unfortunately, I cannot locate the original charger that came with it.) I’m still disinclined to make or get a SuzyQ cable for now.

Here is the article that talks about simulating a live battery failure. The author tried a SuzyQ cable but eventually tried the live battery failure method.

4

So, I unplugged the battery after the laptop was powered. I was able to backup the ROM, and flash a new ROM, but as I was reconnecting the battery I got distracted and forgot to unplug the power, and I managed to short something. :person_facepalming:

So I killed my chromebook.

Not a huge deal. It was sitting unused and it would have been nice to give it a new life, but not a do or die proposition.