Sony KV36FS13

Hello all,
I repaired TV's and VCR's from 1970 until 1997 when I went into industrial electronics. So, I've been out of touch for a few years.
My brother just called me from FL (I'm in NV) and his Sony TV picture went black, but the audio is fine. When he first turns it on a quick flash of light appears on the screen and then it goes black. Also the lights on the front panel flash a code of 4 over and over again.
My first instincts are to say it's probably a high voltage problem, but you are the new experts now.
Any common problems in this area?
Thanks in advance for your response(s).
Regards,
Alan Wise in Las Vegas