PreenFM screen going haywire when connecting USB

[JohnDoe]

Hi,

I bought a pre-built unit a while ago. Until recently, I only connected it via Midi and everything worked fine. When I tried to connect the synth to my PC via USB, though, the screen freaked out and I wasn't able to use the Preen anymore. I had to power cycle and everything went back to normal. The Preen reproducibly crashes when connecting anything to the USB port, either a USB power supply or a PC. Any ideas on how to resolve this?

Thanks
Michael

[Xavier]

The 5V USB is connected to the DC-in after the 5V regulator.
So if your USB gives you a real 5V, you should not have problem.

You may have a bad contact on the JMP2 jumper.. double check it.

Xavier