Mitsubishi VS-50605

I own a mitsubishi VS-50605 and just recently my big screen went out on the blink. A few seconds after turning on the set it turns off. however if i repeatedly keep turning on the set I get a snowy yellow screen. no blue. My tech tested all voltage and it was good. Checked all the CRT boards and their values were all in tolerance. Any suggestion of what this problem my be.