Hi.
It was a problem with the power supply board.
I managed to get a new 1 but took me a while to find 1. And this was 6 years ago and the MXR10 had been discontinued for a while back then.
The new board held up until mid 2020 but then started with the same issue. After some sleepless nights searching the Internet and learning some basic electronics I found a capacitor had blown on the new board.
I swapped it out and all was well for a week or so.
This lead me to think there is a problem deeper in the mixer possibly on another board and this is blowing out the power board.
I gave up with it and bought a controller.
But if yiu use VDJ and change your mixer they won't transfer your licence over.
I have had a big fall out with them and moved to Traktor.
Wish it was an easy solution but Good luck and hope you get sorted with whatever you decid to do