Background:
I got a Toniebox with CC3200. I flashed the custom bootloader and run the backuped image. Therefore I soldered cables to the debug port.
I also got Teddycloud up and running. So CA2.der was patched on the box.
I also updated the new hackiebox sd content, without new flashing.
The box worked pretty fine for about a week.
Then i decided to install the micro sd extension cable.
While dissasembling the box , i droped it on the floor (“the front fell off” … )
I assembled the cable with soft pressure.
When attaching the batterycable the box didn’t boot up. So i plugged in the power cable, and the box worked as it used to do.
Removing the sd extension cable and adding the micro sd directly to the pcb doesnt help either.
The box only runs when directly connected via power cable. If the battery is attached, it gets warm / hot, so i assume its charging. Got it unplugged for the moment until i find the mistake.
i checked the battery voltage at the plug (>4 V) and behind the pcb connector (> 4 V).
Randomly measured some of the battery pins (TP 43, 41 341, 342) and so on, got voltages around 3 V.
But im kind of clueless where to check and measure.
Right now i got a multimeter and a soldering iron.
Kindly want to dig in deep and try to repair it, but im kinda clueless where and how to start?
Should i get a thermical camera to detect potential shorts?
Back to the topic:
Did you connect the battery to the wrong socket (for the speaker)? If you do this, the pcb gets hot. But in the past this didn’t damage the box.
Maybe some solder connection broke. You may check the toniebox-pcb GitHub for some more hints (I assume you know it already).
You may check the datasheet of the charging IC. Possibly you got some documentation about the parts around.
But checking where the heat comes from is a good idea. You may use Isopropanol for that. It will evaporate faster at that point.
I have a Infiray T2 plus, which was worth every penny.
Why? Because it has a focus ring, inevitable for SMD bug hunting.
No need for dual camera overlay stuff. This cam alone allows you to identify exactly the warming parts where you even can read the laser SMD markings.
BTT: if you apply 5V to the PCB, the box boots?
My guess: you ripped off the JST connector on the PCB.
Maybe a very small crack in the PCB trace or just a cold solder joint there finally broke.