18-06-2021, 04:04 PM
There may be a problem with terminology here. Freya's image is showing line scan ringing, a problem in the line timebase. The OP has a problem of video overshoot and/or ringing. This can be caused by problems in the RF, IF or video circuitry as described by Trevor. As Freya says, it should be easily seen with an analogue scope connected to the CRT cathode.
Lifting the 'scope earth as suggested by Peter Scott is potentially(!) hazardous. Many of us have done it without incident but you need to be very aware of what you're doing. Obviously the TV's chassis must be connected to neutral, which is often not quite at earth potential. Make sure there's an RCD in the supply to your bench.
Lifting the 'scope earth as suggested by Peter Scott is potentially(!) hazardous. Many of us have done it without incident but you need to be very aware of what you're doing. Obviously the TV's chassis must be connected to neutral, which is often not quite at earth potential. Make sure there's an RCD in the supply to your bench.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
