I think the problem is in horizontal amplifier because I can see nice A
sweep on R1307 and nice B sweep on R1322 coming in and what comes out
(TP1364) is rubbish. Whatever is switching between the two is not working
Signal at TP1335 is responsible for A vs B sweep.
well. I can see the horizontal position just changing the shape of the
pulse but I think in correct operation this should just be moving the pulse
but not change its shape drastically.
You observed that B sweep works in 5/2/1n mode (is my memory correct?). B sweep is used in 5/2/1n settings even in A mode and as far as I can tell sheet <11> doesn't know whether you are in A or B sweep other than the control signal coming in from connector N4. In sheet <12> N4 is expected to be -3V in B sweep and 5/2/1n mode. What voltage do you see at N4 when you are in B sweep vs A sweep 5/2/1n?
Ozan
