Daytek DT3220 power button flashes green 4 (5) times, no picture
The power supply voltages might look good on an oscilliscope or using a
DC meter, but that doesn't really tell you if the supply is good.
Your TV has an unusual symptom, however 99% of the problems on these
TVs are caused by the power supply. I have had 3220s that won't power
on, the remote or controls on the TV won't work, or the unit blanks out
and all sorts of other odd problems. The power supply can test fine,
but if you substitute it the TV will work fine.
Sorry to say you're up a creek. The good news is that just about any
5,12,24V power supply for a 32:" TV will work if you are comfortable
rewiring the connectors. I have done this a few times and rescued the
TVs from an early grave (I'm actually just about to start on another
one now). The pinout is written on the board, and make sure the power
supply you want to use also has the pinouts marked on the board.