This JBL GO speaker was brought to me after it had been drenched by warm, summer rain. After quick look, it was obvious, that buttons are dead, but what was even worse, the BlueTooth module also had got his ass kicked. After discussion with the owner, we decided to not fix it, because cost would be higher than the same device from second hand. It laid almost two years as sporadically parts donor. One day, I got BT modules dedicated to audio purposes. I'm talking about CSR-8635 with internal antenna. Producer provides two reference designs, which turns out to be very helpful.
On the beginning I was considering resolder only main chip and its flash, but when I saw how much place is between parts and this chip I gave up. I decided to adopt received module to work with original board. I started with removing old module. Next, I had to find out purpose of each pad. It wasn't easy task, but I managed. Let's keep this as a note for others.
I was just about soldering new module, but one fact still bothered me. Track that looked as main power supply for Class-D power amplifier was showing symptoms
of short circuited to ground. I found datasheet to this IC (LM48511) and it turned out that I was right. Internal switching key was connected to the ground.
The fact after this discover, there has nothing left on the board, that would be worth of rescuing (even battery was dead), I decided to save module for better project.
