To test the power supply on this model
First as previously mentioned, I check for bulging caps,
then I check for the st/by 5V, which you have present,
I then short out the control line on the power supply "ps on" to any ground point
on the secondry side of the psu
This should take the psu out of st/by, you will then be able to test all the supplies
The plasma screen on some Samsungs will operate without the signal pcb connected
To do this
remove the connecters between the signal pcb and power supply
short out ps on to ground
then there is pins on the control/logic pcb, short these together
now plug the unit into mains, if the screen now has a raster, this confirms the
power supply, and all the screen drive pcb's are ok,
I would then start looking at my signal pcb, also check the supply voltages to this pcb,
