Hi Rafael!
It's either the battery or something on the motherboard which shorted.
I would try to replace the battery first anyway, just to be like 100% sure.
If that didn't worked, then check the motherboard to see if it still looks OK.
Did you disassembled the device first before you used isopropyl alcohol? If not, then most likely something on the motherboard did short. As the battery was still connected.