Taskalfa 5500i panel problem

[ronsulit]

I bought 6 refurbished 5500i, when it arrived home 2unit had blackout the panel. While we test the others machines all 4 are okay but after the next day when we power on the other one the panel is blackout. Anyone have idea about this problem. Please help thank you very much.

[geltrons]

i also have the same issues

purchased 6 and once installed and configured 3 lost display

installed the main board in a working machine and found the
same problem.

confirmed faulty board.

regards