[SOLVED] Shutdown during boot (was "Battery indicator issue with CM 12.1")

[nmyshkin]

(Please see post #4 as the issue has evolved)

I recently updated my husband's HD from CM 11 to CM 12.1 (the one build in @amaces obsolete folder). This restored some functionality to a few apps that had "moved on" beyond KitKat and preserved the HMDI functionality. Everything else is essentially the same. Except.

Too often on starting the tablet up in the morning it shows about the same battery level as at shutdown the prior evening (maybe 50-ish) and then in a matter of minutes nosedives to 1%. You can see the behavior on the power usage graphic in Settings and it's pretty shocking. There's a vertical line for when it booted up and then *bam*, it drops to essentially nothing. If the tablet is plugged in for just a moment, the battery level returns to normal and everything is fine. It can be disconnected from the power supply and behaves normally the rest of the day.

So this is annoying (moreso because I need to hear about it every time it happens ). I've read the entire (unofficial) CM 12 thread. This issue comes up once or twice and seems to be "resolved" by "calibrating" the battery either with an app from the PlayStore or without. The app seems to just delete a file that would be overwritten at boot anyway from what else I have read on the subject, but the main idea is to drain the battery to an actual 1%, shut down and charge (the tablet remains "off" although the screen is on) until you've got 100% (which has to be judged by the green LED since the tablet is off).

I tried this (with the app), beginning by wiping cache and dalvik cache. It seemed to work for awhile. Then I foolishly suggested doing a backup. I did this with the emmc TWRP and everything seemed to go well except the battery indicator issue started up again...

So we did the battery thing again.... And it was just fine until this morning (not what you want to hear as you sit down to breakfast).

Clearly one could live with this if you always have the charger close at hand, but it's pretty lame. The tablet behaves beautifully in all other respects. I don't think it's a hardware issue as it started right after flashing the new ROM.

One person in the CM 12 thread actually praised the ROM as eliminating this issue which he had from CM 11!

Is this a flashing glitch which might be fixed by reflashing the ROM? I'm loath to do a clean install and reconstruct everything again after such a short time, but I wonder if a "dirty" install (don't wipe data, right?) would be enough. If I reflash the ROM do I have to reflash GApps also?

Suggestions? I'm really at a loss here.

 

[digixmax]

...
Is this a flashing glitch which might be fixed by reflashing the ROM? I'm loath to do a clean install and reconstruct everything again after such a short time, but I wonder if a "dirty" install (don't wipe data, right?) would be enough.

I doubt if a dirty flash would change anything, but there does not appear to be any penalty to try it out as a shot in the dark.

If I reflash the ROM do I have to reflash GApps also?

Not if you don't wipe /data -- basically same as in the case of a dirty upgrade.

 

[nmyshkin]

I doubt if a dirty flash would change anything, but there does not appear to be any penalty to try it out as a shot in the dark.

Not if you don't wipe /data -- basically same as in the case of a dirty upgrade.

I finally got around to this after much complaining about the issue and now I've managed to make it much worse. Before, the tablet would drop from the 50's (or lower) to 1% on boot. Higher percentages of charge were usually safe. Now it goes through the boot process up to the animation and then abruptly shuts down UNLESS the power cable is connected, regardless of the state of battery charge. If the cable is connected boot occurs normally and you can disconnect after boot is complete and everything is "fine".

Except, of course, it's not "fine" at all. Unless you have the charger and cable with you at all times, the tablet has to be left on when you're on the go.

Ugh. Any ideas besides going back to stock and starting over?

 

[nmyshkin]

I finally got around to this after much complaining about the issue and now I've managed to make it much worse. Before, the tablet would drop from the 50's (or lower) to 1% on boot. Higher percentages of charge were usually safe. Now it goes through the boot process up to the animation and then abruptly shuts down UNLESS the power cable is connected, regardless of the state of battery charge. If the cable is connected boot occurs normally and you can disconnect after boot is complete and everything is "fine".

Except, of course, it's not "fine" at all. Unless you have the charger and cable with you at all times, the tablet has to be left on when you're on the go.

Ugh. Any ideas besides going back to stock and starting over?

I came across a post that suggested returning all the way to stock and doing a factory reset, then rebuilding the system.

Once at stock I had no trouble completing a boot without being plugged in. So that is not a hardware issue. I didn't stay on stock long enough to see if the battery indicator behaved, but I'm guessing it did. I prepared a completely new SD card with newly downloaded files and proceeded to do the needed flashing for CM 12.1 w/GApps, using CWM 6.045. It all seemed to go well--even no screen flashing--until I unplugged the tablet so I could easily remove the SD card and reboot. As soon as I removed the power cord the periodic screen flashing that seems to be common during CWM use started up.

I rebooted and got only so far with the CM logo before the tablet shut down.

I don't get it. It worked fine before. What about this process could be causing this odd behavior?

Edit: in desperation I tried flashing The ROM again right over the prior installation. This time I booted into the emmc CWM (6.0.4.6) and waited for the tablet to calm down. Then I unplugged it and flashed the ROM from the ext.SD card. No error messages. I held my breath and rebooted. I got to several iterations of the cyan android face and then it shut down again.

Next I flashed TWRP 2.8.7.4 to emmc and tried flashing the ROM from the ext.SD card that way. Same result.

The battery charge shows 80% so it's not like the tablet is running on fumes and it's hard to believe the problem is the battery or the indicator since none of this happens on the stock ROM.

I just don't get it. We don't want to go back to stock but I don't understand any of what is going on. Initially CM 12.1 was working beautifully. Then the battery indicator issue started. I addressed that as best I could and when it seemed like we had that on the run I did a backup. That resulted in this shutdown issue. You can use the tablet just fine if you never turn it off and keep either the charger or a portable power pack handy (don't forget the cable!).

I really need some help troubleshooting. I'm willing to try just about anything.

Edit: indeed, the last resort was to buy another HD... But it turns out the booting issue was caused by an SD card that somehow was not properly prepared as 0x0C FAT32 LBA but was instead something else which I don't remember now (something with a "b"). Anyway, once a new card was carefully prepared, the tablet booted fine without being plugged in. Whether this also solves the battery indicator issue remains to be seen.