RCA hdtv picture goes in and out.

The deflection board needs replacement. You need the PSB260 deflection board available from www.tvrepairworld.com

need to replace power supply board to resolve this issue

U have tools,can u do basic soldering,and understand basic electronic?Yes.Take ur tv aparts.Take out the DM power supply board check for dying,soon to be dead capacitors.These capacitors are alway bulges or puffing up on it tops.U replaced these dying capacitors,u will solved this power light blinking problems.Try website like Tvrepairworld.com might still sell those prepack capacitors repair kit for the RCA DLP tv DM power supply board.

u have a bad capacitor on power supply look close at power supply section the value 2200UF 25volts

Flyback transfromer is defective and needs to be replaced.

Did you replace the convergence power supply board, or the Convergence board?

it is going into shutdown, alot of things can cause this, bad solder connections on the power supply/sweep module, shorted flyback and/or horizontal output transistor, could even be shorted picture tubes. most likely it's bad capacitors and solder connections on the power supply/sweep module, needs at least some minimal soldering skills.

power supply problem check capacitors...caution
high voltages..large capacitors retain nasty charge for a long time.........

Resolder all poor connections on power supply board and this should fix your problem.

Check 3 capacitors on Power supply/deflection board cp150 2200uf 16v if it is bad replace 2 other caps in same circuit cp111 cp114 220uf 35v