**WARNING**
For anyone with a Carpuride W702 I strongly advise against trying to update Firmware using one of the numerous files posted online here.
I tried this and it caused a "black screen" which is widely known to be an issue. In my case it also prevented the touchscreen from working.
After much experimenting I found out the following...
1) The black screen occurs because during initial power up the unit encounters corrupt code in the Bios and immediately switches off the screen backlight and the touchscreen. The unit still boots up as normal and you will see the various app icons if you shine a torch sideways at the screen.
2) Fortunately you do not need to touch the screen to initiate another Firmware update as it commences automatically after a countdown following insertion of the micro USB card with ISPBOOT.BIN file on the FAT32 card.
3) There are obviously many different derivatives of the same Firmware Version so just because it says the version is for example Vs 1.11, it does not mean it is appropriate for your W702. There are different chunks of code in any Firmware update and they ALL have to be compatible. The analogy for me is the Software version on my RT. The TFT says 014_015_020, but as my workshop says, that is just the TFT version and there could be different software version running the ECU.
My W702 Firmware is shown on the screen as -
SDK Version 22.0.11.0.0.0.1.2
CUST Version LT-M702D-S9-V1.22
MCU Version LT-702S2-921-V1.11
BTTR Version SO40-23.08.15.11
I tried all of the files posted on this forum and none of them exactly matched my version, and they all caused the black screen. I then got a specific download link from Carpuride and instantly the update started the screen came on full brightness. Issues resolved. Now works properly.
I suspect that different countries have different Bios code, or multiple design changes over time to the W702, and they are not all compatible. The actual OS and Apps are probably the same, but a Firmware update also rewrites the Bios and these are clearly different.
Not sure if Carpuride have worked this out yet that users sharing Firmware online is probably the source of their need to warn customers "not to upgrade firmware because some customers are experiencing black screen issues". A better solution would be for them to implement more stringent checks when the ISPBOOT.BIN file commences execution and stop it if it is an improper version.
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I have highlighted the warning you have given.
Richard