Mitsubishi FX20 contact problem

We have 1997 Mitsubishi FX20 wire machine which we inherited about a year ago. It worked fine for a while but since about 5-6 months it started to show a contact with the IP settings of 4 and up. It works fine with smaller power settings. Initially that was happening only once in a while, now it seems to be working correctly only once in a while. I checked pretty much everything for any broken wires, so that is out of question. Beside that it would show the contact constantly not just on higher power settings. Did anybody experience something like that? Any suggestions what could be wrong?

Thanks,
Pete

On top of the generator is a cover covering fans and some load resistors, check the resistance of the 2off 4ohm resistors, they are wired in series so should read approximately 8ohms. Sometimes we see 1 of these resistors go open circuit.

Thanks for the reply.
I checked them and they seem to be fine.

Check the 6 avr's on the back of the sub unit.

Is your machine a straight FX machine or is it a FX20K machine?

We hace a FX-20, Shows contact anda have that red led in MW416, This happens when we want to start to Cut. Someone know what happens?