I purchasef a used DT25 112 combo 2 weeks ago.
It was working perfect, no issues at all, but I decided to install firmware version 2.
So this morning I tried to upgrade but failed with the code 8000000A error and the amp is not responding now.
The steps I followed were
1 Connect the amp via an Alesis USB-MIDI cable to my Mac running OS Sierra
2 Launched Line 6 Monkey, which detected the DT25 with firmware 1.0
3 Clicked the update button and after a short time I got the 8000000A message
4 When restarting the amp and Monkey, the amp does not get detected anymore.
I googled for problems and decided to try it again with the dowloaded file. No succes, same error.
Now the amp is useless.
I searched and tried the safe mode with channel B toggle, the pinching topology and pentode switches, but nothing restores the amp to its default.
I tried several times to upgrade, even on a windows 10 computer, but the problem does not get solved.
Anybody here that can help me with this ? I loved the amp as it served as a practice amp that was not too big and versatile enough.