My Bambu Lab A1 has stopped detecting power-loss recovery. It previously offered Resume Print after power cuts, but now after an unexpected power loss it boots normally to the home screen with no Resume option and the interrupted job is gone. The print head remains in the position where the power was lost. The printer is running the latest firmware and I have already tested the recommended troubleshooting.
I don’t think it’s ever worked properly anyway. Printers would try to resume but have yet to see a good resume posted.
The wiki has a good technical explanation of how power loss recovery works. Note that for the function to work, the system has to detect a loss of power and be able to act on it before system voltage drops below a usable level - actually quite remarkable imo.
If the power became unstable prior to cutting out, that may not be recognized by the system. Similarly, if the power return is atypical - flicker restarts, or multiple on/off cycles - that could impact things as well.
I think before you truly state power loss recovery isn’t working, you probably should do some additional tests of the function - switching it off mid-print, waiting a few minutes, then switching it back on to see how it handles a “clean” power loss and restore scenario.
Another factor is the time issue. The longer power is out the more a model will cool and shrink. People who have had filament run out and the printer sit for a while before resuming get visible lines in their prints even if the print resumes perfectly - which it can since the interruption wasn’t due to power loss.
@FerneyGraphics - What many do (including myself) is run with a UPS. Mine doesn’t always switch over fast enough so I usually print from the UPS with the mains power off. But there are definitely ways to make power-loss recovery a non-issue.