Sony Trinitron KV-13FM12 flicking

[liammc00]

This set has a very good picture except for the problem that image brightness flickers. If turn the tv on with no signal or a signal you can see the brightness of the raster flicker. It reminds me of watching an 8mm movie on an old projector but worse. Also the on screen menu doesn't flicker. My first thought it might have a bad cap as it does get little bit better once it has been on for a couple of minutes. I did test them but couldn't find any that had bad ESR.