This could be a cold solder on the CRT socket assembly, bad connection between the focus grid of the CRT back to the focus supply, or a defect in the high voltage multiplier, and or the CRT may be failing.
If you are not experienced in TV servicing and equipped to do so, it is best to give the set out for proper service. There are some serious safety issues with working inside of TV sets.
--
JANA
_____
"simon hanlon" wrote in message
news:dq1ftk$lk8$1@news8.svr.pol.co.uk...
Model number 284248WNS
Powers up ok then immediately the screen has a yellow tint then changes to
red then blue...goes out of focus and back to normal..cycles like this
.takes about 6 seconds to go through a complete cycle.
any ideas