WFS210 probe inputs ded?

Hi, I have been using WFS210 for a long time. Mostly connected to Lenovo PC over USB. That way it was most reliable since the connection over WiFi mostly did not work and the way to switch over from Demo mode on Android tablet app I found so crazy, that I gave up trying even if it worked sometimes.

However yesterday the instrument stopped showing any trace of yellow or blue voltage track. The LEDs work, the communication works (the PC indicates the COM port and connects), the Demo mode works, but when I connect over USB (which obviously also works) there is nothing in the picture even if I select GND on CH1 or CH2 (this goes for both PC program and for Android app). Also when I select calibration, the dialog “Calibration in progress” stays there forever. Does this mean, that both probe amplifiers are gone? Is there a way to get it fixed? Is there a way to diagnose the issue?

Thanks for any help.