Posted August 27, 2024 at 18:33 GMT
Hi folks,
I'm giving you some updates following my previous post.
My battery was definitely not dead. Maybe it is worn but still holding good. The super capacitor was dead but had nothing to do with the boot loop issue that some people including myself were experiencing. I removed it and still waiting for parts but its absence doesn't cause any loss or improvement so far.
However I managed to restart my tablet, maybe by luck, I don't know, but here is how I did it and what I learnt:
This tablet is probably built on top of an ASUS TF300T (NVIDIA Tegra 3 T30L). So similar debug process applies.
If you open your tablet, you'll find close to the capacitive sensor PCB on the mainboard different test point that you need to solder very thin wires to. Especially RESET and VOL -. Please disconnect the battery before.
By following the process of "fastboot" for ASUS TF300T tablet, which is, while you're getting the boot loop issues, you maintain the other end of the the Vol - (Volume down) wire to the main board heatsink/shielding/ground, briefly touch the end of the Reset wire to that same ground and hold the Vol - wire end to the ground chassis of the main board (not the bezel by the way, it's not connected to ground). Then keep it like this until a wheel appears, trying to restore something. Wait before the whole tablet reboots before removing the Vol- from the ground. Repeat several time until it works. At least this is how I've done and what worked for me. I'm not sure I fully fixed the issue for my tablet but I'll be curious to hear from others if you managed to repeat that process.
Let me know if you want some pics or details for helping you in this process.
Cheers,