FlashForge AD5M Pro firmware updates failed from stock V2.7.5. Solution found.

[AgentZillion]

TLDR: Flashforge AD5M Pro stock firmware 2.7.5 not updating via OTA. Almost bricked with USB update to 3.2.7 or 5.1.2. Fix: firmware V2.7.5 (and 2.7.8) required USB manual update to V3.1.3 as stepping stone, eventually to 5.1.8.

Posting in case this saves someone time who also has the same glitch that wouldn't allow updates to update. I bought a Flashforge Adventurer 5M Pro from eBay as "open box, 0 hours return." I get it home and it prints a benchy just fine, but once connected to the internet, wants to update the old software.

Failure #1: Over The Air update from 2.7.5 (and 2.7.8) would report "successful" and reboot normally to the home screen, yet the version never actually changes and would prompt again to do an update. No warnings or errors, just an endless loop.

So I attempt a manual USB update to a popular intermediate version, 3.2.7.

Failure #2: USB install to 3.2.7 (and 5.1.2) shows "Upgrade Completed. please unplug the USB and restart the printer." After reboot, screen shows "Upgrading MCU, please wait... Please don't turn off the power." After 30 seconds, screen goes to the black and white "FlashForge" welcome screen, yet hangs indefinitely (waited over 10 minutes) and doesn't progress to "Initialization..." screen or reaches home. Power cycles result in the same "FlashForge" welcome screen. At this point the printer seems bricked, yet it'll still accept a USB manual install attempt. Luckily a USB install to 2.7.8 worked and the printer booted up correctly to home. I tried doing a USB update from working 2.7.8 to 5.1.2 (the newest posted version), yet resulted in the same Failure #2. So I again did a USB update to 2.7.8 and it initialized properly.

Solution: The install combination that worked and eventually landed on the most current version, 5.1.8.

1. From 2.7.8 did a USB flash to 3.1.3; boots cleanly to home. Yay progress.
2. Connect ethernet and OTA update from 3.1.3 to 3.1.4; boots cleanly to home.
3. OTA from 3.1.4 to 5.1.2; boots cleanly to home.
4. OTA from 5.1.2 to 5.1.8; boots cleanly to home.
5. 5.1.8 is the most current version, no update necessary.

Takeaway: 3.2.7 and 5.1.2 aren't broken firmware. They seem unreachable as a direct jump from 2.7.5/2.7.8, but install fine once the printer passes through 3.1.3 first.

Side note: the front touch power button was unresponsive unless at the home menu after initialization, so required using the rear switch.

Good luck out there. Thanks to the community for all your efforts :)