/diy/ - Do It Yourself

TIFU. long story short:

>got free chink tablet w/ puffed battery
>got it fixed by some guy (inserted two smaller batteries in parallell)
>some day it started acting wierd, turned out one of the terminals broke off
>trying to resolder
>shittymetal32.mkv
>solder won't stick
>fuck this, replacing it with 2 old phone batteries.
>won't charge, screen got warm
>turn it around, voltreg IC burns my finger
>panic_instant-desolder.gif
>looking at the mainboard for hours, why is it drawing 2 amps
>seems like some pins on the LCD connector are soldered together
>no worries, can solve this just by using a metric shitton of solder flux + coppe solder soaker
>at least there are less shorts now, and they're placed differently
>reconnect batteries, suspected VREG IC still electing a pope
>still drawing 2 amps

>I was told that this should be the batteries if that really was the only thing I replaced
>no.png
>starting to give up
>turned out it was the batteries (tested it with a 18650, which obviously won't fit in it's case)
>screen is now 16 bit color
>fixed, it has good colors again (altough seems some are shorted, idgaf)

>using 3 smaller batteries now
>screen now got 8 bit colors
>how.jpg
>shitting again with the connector, now I've got a blank screen
>I had this awesome idea that adding some solder helps removing the solder stuck on pins
>now it's all covered in solder which I can't get off.

what do?

This is just a chinese shitty tablet but I'd love to get it fixed. It would be so satisfying.

How do I fix this?