Found - MTCD Schematic. A most valuable find on russian android car audio forum and attached here.
The schematic corresponds to a GS Mainboard I have as a spare part. It varies to my JY board in terms of USB operation, with this board OTG...
"Factory" Recovery for MTCx PX3, PX5 and PX6 SOM.
Finally - OTG for all without modifying your head-unit. With only basic electronic/soldering skills, get OTG and fearlessly flash or recover a 'bricked' MTCD/E (HCT printed on SOM) Rockchip PX3...
This Post details how OTG/LOADER can be achieved to recover a corrupt PX5 or PX3 - any RockChip MTCx SOM
Update 2/2018 - anyone can make a gig without modifying their main board. BUT FIRST try a USB port, some have OTG out of the box.
MTCD Oreo ROM Extract/Dump is here: ROM
An example of XDA teamwork - Thanks to: ikerg
xdamember2 RedScorpioXDA kumarai
Solution see post 159, thanks kumarai
Process video again thanks to kumarai
- note the approx 5 minutes of grey sc...
This thread is to document MCUs found to be cross-compatible between MTCD units, which includes PX3 and PX5 variants, which share identical mainboard hardware and MCU Chip STM32F091.
The following MTCD & MTCE (as of v2.56) MCUs have been valida...