Did you fix it? I have an old Mi3 phone that was never really used. I forgot to turn it off last time I charged it so it was stored empty for a while. But the battery charges almost like normal. 1st time I tried to turn it on, it would go to the Android loading screen but just stay there. I tried to clear cache in Mi Recovery but didn't work. I left it on the Android loading overnight and the phone was dead in the morning. I charged it again but this time, now there is a boot loop. I can still access Mi Recovery but clearing cache completes instantly, not normal. Soon after, now I can no longer access Mi Recovery, only Fastboot. I flashed a new rom (few times) it completes but still bootloop and can't access Mi Recovery. Can a battery problem really cause this problem, even if the battery takes a charge and seems to have decent capacity?