Central Switch doesn't work

[FASTman]

Hi,

I bought a new oscilloscope DS0138, but now after the set-up I've the following problem:

- It works correctly when the switch are CPL is = GND or DC, SEN1 is = 1V or 10mV, SEN2 is = X5 or X1.
- It DOESN'T WORK properly when CPL=AC or SEN1=0.1V or SEN2=X2 (central switch)

When I put the switch in one of this central position the yellow settings on the botton left doesn't change BUT the graph changes correctly.

From what can be taken this problem? An assembling problem?

http://i.imgur.com/pJT3wXp.jpg

[OldGrey]

Mine display ok.

I guess if there is a bridged solder joint or a dry joint, it won't change with the switch.

If it's common to all 3 switches, that might be clue.

[krazydarcy]

As the switches work in 2 of 3 positions, checking the schematics while the 3 sense we can see the circuits are identical yet are seperate. R18, R21 and R24 must allready be correctly mounted otherwise the dc 10mv and x1 positions wouldnt work. ( r18, 21, 24, r9, r20 and 23 needed for x1 10mv and dc positions to get to the ground line).
As you appear to be using the stock supplied switches which will only mount one way around, i suggest checking your switch pin soldering.
I had switch wiring issues myself as i was doing a custom case for mine with rotary switches.