If you don't know what you're doing - don't put your scope anywhere near the TV!I have a meter to test capacitors. They all read 2 or 3 microfarads over what is printed on them. Don't have a scope or isolating transformer. Wouldn't know where to put a scope probe on it. Just seems a waste to dump it.
The scope should be earthed, parts of the TV PSU are equal to the mains peak value, the bit you might think is earth/common is actually about 320V negative (for 230V TV).