Agilent U1620A Channel 2 not working

[TubeCharley]

 Hello I recently received an Agilent U1620A for repair.
Channel 2 of the scoop does not work.
The green line does not appear on automatic triggering.
If you do the self -calibration function, an error code will appear channel2 offset: 0x8ff.
Channel 1 is doing well and the meter function.
I requested a service manually with schemes at Keysite, but these gave a very typical answer.
That with this cheap (7000 euros mind you) handheld, equipment does not deliver manuals with schedule.
And that I have to offer the device to them for repair.
Can anyone help me with schedules or block schedules or has some one a different idea to repair this oscilloscope.

[m k]

There are two channels, so you can expect two pretty equal routes in.
If nothing else is available you can always start comparing.

Then if the problem seems to be an ASIC I guess you're stuck.