[MTCD Hardware Development] marchnz:
"Factory" Recovery for MTCx PX3, PX5 and PX6 SOM.

UPDATED" 26.06.2023 - Before doing this, try your Headunit USB cable first - Some headunits support OTG directly on the headunit USB cable.

Come here after using paid Software "Mod" tools like Modinstaller?

This method is the factory method, which can completely recover a "bricked" SOM, recover from failed "modinstaller" or failed upgrade of Paid mods.

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, PX5 SOM.

See attached pics for making an OTG cable from a USB cable and two resistors.

Resistors are 12K and 15k (22k is probably better) or anyone of the following. combinations. These resistors are necessary as 'voltage dividers', with a value between 1.8v and 3.3 OK. These simply place a logic '1' on recovery and USB-OTG to 'tell' the SOM to go into OTG recovery mode.

R1 | R2

-------------------

1K | 1.8K

2.2K | 3.3K

10K | 18K

12K | 22K

Get Windows Driver [Driver assistant - v5.11] and [RKDevTool 2.93] for direct/OTG SOM flashing:

1. From a chinese Firefly site here

or

2. My Google Drive here

[RKDevTool] .ini file is set English, otherwise tool will be rendered in Chinese.

This tool for dumping / getting full backup of SOM

Excellent tool, thanks @RedScorpioXDA

Note - all tools and driver have equivalent Linux versions.

26.06.2023 - Android Tool is now RkDevTool

PX5 Android 9 Update.img - suitable for flashing via rockchip tools - https://yadi.sk/d/umCvHqCDzHccr/RockChip PX5 Android 9/YB

The image is located in px5 android 9/yb. The file has "_img_" listed in the filename.

Note Android 10 has an img file too - located in px5 android 10/chs.

PX5 Android 8 Oreo full Partition extract suitable for recovering SOM, flashing via rockchip tools - https://drive.google.com/drive/folders/1P703unZDA_TdRzl6fjkkb-YUB-KpTViW

Using the RockChip RKDevTool:

For OREO: Unzip and flash all partitions in the ZIP file [px5_OREO_Full_13032018-UseToRecoverOrCreateNew.7zip here

For Android 6, flash the latest update.img file in RKDevTool

There are guides to partition flashing found on the internet, would be great if anyone could contribute by posting step-by-step instructions or a video to assist others (there are now posts in this thread...)

A generic guide to the RockChip RKDevTool, flashing partitions or image files is here as previously posted.

Credit (thanks!) to @scorillo_ro for the detailed image/connections diagram.

Worst case - SOM doesn't respond - force 'maskrom' detailed here explaining what MaskRom is and here on how to for your PX5 (px3 is similar.) Steps are: Power Off SOM and disconnect USB to PC. Use Tweezers, apply power/connect USB. Hold until Windows Device chime is heard (within about 2 seconds of power on.) See attached pic.

Warning : Use thin pins for OTG cable in order to avoid the damage of the SOM connectors, although along the thread it has been noted many times that damage to the SOM socket is very likely to happen if thick pins are used...OR buy SOM header from Aliexpress, digikey etc.[/COLOR]

17/11/2019 - Edit: Corrected URL for Windows and Linux Rockchip tools

04/04/2020 - link to px5 android 9 full update.img

20.06.23 - Update broken links to driver and tool. Update Name of tool (was) Android Tool - (now) RKDevTool