Kenwood firmware update failed, now stuck in a loop.... [Resolved]

[robwilkinson]

Thanks to this thread I managed to sort my update this morning, and just wanted to add to the solution in case anyone else ahs the same issue and wants to give it a try.
I have a Kenwood DMX8020DABS. I used a good quality (SanDisk) USB drive, 32GB and I got the looping update error after the first part was updated (after which it restarts the system to finish the update).
After reading this thread, I used a smaller (8GB) generic USB (I have a whole box of them to use to send client's photos, and they were only a few £'s, so I expect aren't that great quality).
Worked a treat. Thank you @YellowHound for your original experiment!

 

[smileyshak]

sharing my experience with upgrading the DMX4707S. I download the latest driver and copied them to a flash drive and copied them to the root folder. Now this flash drive had other stuff on it which I had not deleted and I did not check specifically for Fat32. (It was some default FAT formatting).
Anyway the kenwood receiver detected the file and prompted me to the next step to Select ARM or MCU and I selected ARM as per instructions.

Now the problem started. The screen just went blank. I waited for about 3-4 minutes and no update messages. I pulled the key out and restarted the car. And now the kenwood screen should not even show up. It was showing completely blank. I thought that I bricked it.

Then I tried the following steps which resolved the issue
1. Emptied the flash drive that I was using
2. Used a windows computer to reformat it to FAT32
3. Just copied the 3 files that are used for the software upgrade to the root folder.
4. Now I put the flash drive in the car and restarted it.
5. Big relief. It started the software update. It finished the ARM update and then reboot and then I did the MCU update.
Moral of the story. The Kenwood receiver is a bit picky.
Make sure you start with a clean formatted flash drive formatted as FAT32 and only keep the files that are needed for the upgrade.
Hope this helps someone else.

Before the upgrade. My hands free Bluetooth phone call button was not working. After the update it got fixed. So the upgrade is helpful and it will fix a few quirks with the base software.

All the best !!