Anybody knows what's going on with CRT on a oscilloscope that goes into a horizontal line ? It used to be intermittent and usually snap back to normal if tilted the scope about 120 degree backward and then restart. Now it seem to be permanent, it is a old LeCroy LC564A
Thanks for the feedback JimB.
I was thinking on same line as well, but without a service manual or schematic of sort it would impossible for me to DIY this scope. There is virtually no such documentation available for LeCroy scope online... why is that ?!
as i saw in the pic the line has two gaps in its beginning and ending.
it is more like the component test mode in oscilloscope.
maybe something is wrong with that switch. put a resistor and see what happen.
excuse me that i was late.
every oscilloscope has a component test part. it is like a hole usually under the crt screen. put one pin of a resistor in that hole and the other pin on the ground input of channel one. and see what happen.
Almost all oscilloscopes have a test signal output (Square wave, about 1 V peak-to-peak). I request that you connect a probe to one channel (Channel 1 or 2), switch the channel coupling to AC and connect probe to test signal. If you see a square wave being displayed, then it will prove that the Vertical AMP is working.