[MTCD  Android Head Units Q&A] darkspr1te:
The two chips at the top , one has burned trace and the other is really burned, These are TI 4803/A mosfets and are used to send the ACC/ILL/REV signals to the head unit or reversing camera when replacing a OEM head unit that receives CANBUS/J8135 K/KKL style databus messages for headunit switch on(e.g range rover when you open door or ford RS when you press brake or go into reverse) . It will normally come part of a loom that attaches to the android heat unit and the ACC and ILL wires (red and blue) will goto this box instead of connecting to the cars ILL/ACC ,

Repairing the wire and replacing the two mosfets will fix this no doubt, also the reason it failed is no doubt a short on ACC/ILL between this unit and the head unit and ground. Also see my discussion on canbox's and reverse engineering to see possible ways to tell what box you have and which open source software might work on it to add/tweak features.

The MCP2515 is CANBUS to spi chip and the JA1054 is to interface with K line and KKL line comms , 7805 is 5V power with another circuit to provide 3.3v and some small switching transistors.

this attached picture 'should' be a match and as you can see it says ACC out

Of the box types you will see there are 3 main types

original 8/10 pin single row units providing SWC and k line/canbus only often stm8 MCU or a 8051 core mcu

16 pin clones using STM32f103 or GDM clone arm chips (see my git repo for open source code for these)

16 pin & 20 pin clones: originals using pic16/pic32 micros and clones using china clones of pic microchips as you have with your model.

Also there is two sides to this coin.

While the canboxes talk to the car they only act as a bridge to the right software on the droid side, originally it was a few companies who patched the current android to talk to a serial port (uart ) and query the canbus via the canbox as a bridge.

So that brings up the droid side of the software, depending of what brand your choose ,e.g raise and what brand e.g vw and what car , eg golf would mean you see all the door open/close, ac controls, car data no problem but if you choose another brand like hiworld and leave the car make /model the same you will not see all the same info , you will only see the effect like speed control volume, dimmer when light on, steering controls only.

This is seen in the source code for both the android app and the mcu in the canboxes

Finally there are some exceptions to the above pinouts ,

in toyota models the K-Line side is replaced with AVC-Lan circuit , in merc cars the K-line is replaced with inhouse tweak of j2354 standard so the electronics are different on those pins , in vw models there are two K-lines(SWC and AC controls) and canbus and canbus is readonly (door/window status)

in nissan models there are 2k-lines 2 canbus systems in newer vehicles but old ones rely one pioneers AV lan style system if there was a cd player.

ACC = accessory position of ignition

ILL = illumination signal 12V from lights

*edit*

In some cases i have seen the mosfets ILL/reverse camera/ACC but normally i see only two, and it will vary on the device maker if they use a mosfet for the camera (allowing the box to power the camera fully) or not and use a darlington array to a trigger wire on the camera (eg the cheap 3 wire + video cable style) , the more modern units that also fitted to cars with radar and 360 cameras use a mosfet.

hope this helps

darkspr1te