Hantek 2090 Channel one problems

willisodhiambo

I am using this oscilloscope for vehicle repairs but I have a big problem with channel 1

Whenever i automatically acquire a waveform for something around 5volts, it will automatically set both channels to very high vertical resolution, usually around 20mV. No problem with that. I then manually alter the scale to around 2volts and I get a beautiful can bus wave form but...

Channel one always disappears from view whenever I adjust the vertical scale. I am unable to acquire it at all after that unless I return to the auto scale or reacquire waveform. Channel 2 is ok, I can move the curser left of the graph and bring it into view at any scale.

What could be the problem? I need to be able to compare channels 1 and 2 for can H and L buses but tool is now only usable as a single channel oscilloscope. it seems channel 1 is completely unable to read anything at vertical scales set greater 20mV

Any ideas?