[bgk283]

Hi, after reading up on the weak spots of these chassis, have seen problems with the 6GU7s with the ground stakes on the chroma board, has anyone any input on the 12BY7A, when the set is first turned on it has raster, after a few minutes the picture goes dark and the 12BY7a has gone out, sometimes it comes right back but after substituting a new one the problem remains...Is there a similar problem with the ground stakes on the board near this tube too? is it a common thing? Or maybe a problem in the circuit that comes with age? any input would be appreciated. thanks Bruce