How to recover from a failed firmware update on Megarevo's R8KLNA

1. Power-cycle the inverter. Open the top cover and make sure the LEDs on the control board go out before turning it back on.
2. Re-try firmware upgrade via USB. Usually you need to use your USB-A port on your laptop with a USB-A to USB-C cable. Steps #1 and #2 will usually work in most cases.
3. If the USB port doesn't work, try doing the firmware upgrade via RS-485, but you need to use a different file. When you run the Hybrid app with nothing connected and click upgrade, it will create a file ending in something like .bin_add_header.bin in the Hybrid/bin folder. That's the one you can use to upgrade via RS-485 (in the 485-Upgrade tab of course). This will take probably 8-13 minutes. You can do this with either the .out or .axf file.
4. If the .out upgrade still fails, then you may need to get your hands on a TI XDS110 programmer and create a special cable to flash the .out file directly to the control board. Use the UniFlash program to flash the .out firmware.


Source: user WrenchLight at diysolarforum
https://diysolarforum.com/threads/megarevo-8k-firmware-update.54948/post-973610


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

fromport said:
Is there any way to know if the RS485 connection is working ?
Will "any" RS485 adapter work or do you need a specific version to work with the program ?
I think got the wrong one, XDS100 vs XDS110 
Can you tell me about the special cable that you were talking about ?

WrenchLight:
If the RS-485 connection is working, then during firmware update, the hybrid app will show the progress bar making progress. Pretty much any RS-485 adapter will work.
Here is the super hard way to flash the .out firmware and recover from a failed .out firmware upgrade if all the above suggestions fail. The XDS100 should work the same as the XDS110. You'll need Uniflash https://www.ti.com/tool/UNIFLASH to upload the .out file. 
You need to disconnect all power from the inverter, disconnect both power connectors from the control board. Near that two-pin power connector, there's a relay. Remove the two-pin jumper next to the relay. Power the two-pin AC port with DC 220-350V (needs roughly 20W). It must be DC. AC will be bad, even though it runs on AC during normal operation. Connect your programmer to your PC and to the white 4 pin connector on the control board; it's toward the middle of the board on the edge closest to you. Left to right pins 1-4 are TCK, GND, TMS, 3.3V. See pages 97 & 98 https://www.ti.com/lit/ds/symlink/tms320f280049-q1.pdf for more necessary info on the connections. Flash the firmware using UniFlash. (The first time you use your programmer, it will probably update the firmware on your programmer.) Then disconnect and put all connections back to how it was.

source: https://diysolarforum.com/threads/megarevo-8k-firmware-update.54948/post-975581

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