I have a Toshiba 61H71 where the picture gets distorted and flashes and somtimes it will shut off the TV completely. After I unplug the tv and wait and plug it back in it will come back on. Inside around the voltage regulator Q801 and Converter Transformer something is making a hissing sound when the problem is happening.
This is a very common problem with these types of Toshiba TV set. First thing you need to do is to unplug the TV set. Take off the back of the TV set and look around in the power supply for two larger types of capacitors. They should be marked C809 and C810. These capacitors over time come loose from the printed circuit board and needs to be re soldered. If you do not resolder them, and hit the set to make it work, one day it will blow out a fuse labeled F860 on the printed circuit board. If you have no printed circuit or solid state repair experience, play it safe and call in a pro to assist you in this repair. They should not charge you very much for this repair, and can for sure be done in the home, if indeed this is the problem with your TV set. By the way, if you call an authorized Toshiba repair center to assist you with this repair, the service bulletin number is TV020. Good luck, and let us know how you make out with this repair.
I pulled out the board and examined the Caps :C809 and C810. The solder joints on those two seem fine.
Not long ago I had a convergence problem where I went into the Service menu to line up the red, blue and green. It seemed to help with the convergence but when I press the touch focus it comes back with an error. Could the 2 STK392-110 chips be going bad and causing the television to shut off?
PS. I do not have a scope but I have a meter and soldering equipment.
It is a possibility, but I would also resolder those capacitors just to be safe. Toshiba has a service bulletin out on resoldering those caps, so it is not something to take lightly.