Sharp C-1410 no power (smps issue)

[ostlar]

I received a Sharp C-1410ND a couple of days ago, it was working fine for about two hours with my Wii connected, I was getting some snacks when I came back to a dead TV. Didn't hear any unusual like a pop or crackle.

Opened it up to check if anything had gone fubar, but no sign of that. Plugged it in again, was met with a whine that started high in pitch and went down until it halted. I have uploaded a YouTube video
with the sound of the power supply issue. The sound is coming from the power supply area.

The issue is most likely in the switch mode power supply, I am suspecting the primary side.
After reading up on these power supplies, I started troubleshooting.
Started with checking for cracked solder joints and reflowed some suspicious ones. Checked the diodes, most of the resistors, capacitance and ESR of the electrolytic capacitors. Everything checked out fine. Checked the voltage on the main filter capacitor C706, got around 335V. On C710 i get 72V.

Seems like resistor R709, R710 and R711 is the only thing getting hot on the board according to my thermal camera, around 35-50°C. They are marked in yellow here:



What could this issue be? It sounds like there is either something in the feedback circuit that has gone haywire.
I only get about 15V for a brief moment on C635 on the secondary side, so something is happened.
Maybe a short that kicks the PSU into overload?
I have not checked the ceramic/film capacitors as they are usually okay, but might be worth a shot to check them too?

The schematics for the TV is available on ElektroTanya.

Appreciate the help.