10-09-2018, 11:27 AM
The whole point of the castellations is to put maximum stress on the sync separator. Several possible problems, mostly as Lawrence says, video getting through the sync separator. Old time TV service guys usually had a pretty good idea of what was causing this sort of fault. I tend to reach for the 'scope and look at the waveforms around the sync sep.
I assume this set is "live chassis" with one side of the mains conencted to the chassis. If this is the case, the correct and safe way to conenct a 'scope is to use an isolating transformer to supply mains to the set. There are other methods that are less safe (old hands may well have used them) but I won't describe them here.
I assume this set is "live chassis" with one side of the mains conencted to the chassis. If this is the case, the correct and safe way to conenct a 'scope is to use an isolating transformer to supply mains to the set. There are other methods that are less safe (old hands may well have used them) but I won't describe them here.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
