Panasonic TX-32LED7FA, Dead Power unit.

[vest7]

290 volts are present at pin 23 of the IC-circuit F9222L in the PSU.
The VCC at pin 7 varies between 10 and 15 volts.
But the F9222L dont start oscillating.
Can´t find any broken component.
I have changed the F9222L but the fault remains.
Chassi:GLP22M.I have the schematic.
Need help.