I have a Partner 1 with a cent 5 controller. When the machine runs at 6000 rpms the screen goes out. It doesn't do it at any other rpms. I don't normally run that high, but I was running some carbide endmills in aluminum. When I first try to run it at 6000 rpms after the machine has been ran at other rpms for a couple of days I can run it at 6000 for about 5 min then the screen will go green the black. Then I have to shut the machine down and restart it. Once it does it as soon as it goes to 6000 rpms again, the screen will go off. It stays on at other rpms all day. Any ideas?