Hello everyone
I have a Samsung HCL4715w which we have stopped using due to it not fully powering on anymore.
The problem started with a single color fading in and out while watching. Then the entire image started to shrink into the top half of the screen.
Now the set will not power completly on. when plugged in the standby relay clicks and the you hear the flyback energize and see the neck on all three crt's begin to glow and after about 2 seconds the relay shuts all down and restarts the cycle.
Don't see any resistors burned in the "POWER" board and all meter out ok. all caps look ok except one of the large filter caps has a slight bulge at the top but nothing extravigant. My meter doesnt go to 22000uF to check those caps. If i unplug the "SUB" the relay hits once like it should and holds. with "SUB" board unplugged voltages check out on the output of the "POWER" board. With "SUB" board plugged in voltages on "POWER" board get pulled down right before re-cycling of the relay 34v+ gets pulled down to 26v and same on 34v- as well, 13.5v and 8.5v sources also pull down as well.
There are no signs of crt coolant leaks dripping on the micom or any other boards as mentioned in other threads.
Where should I look next? Is this a weak cap draining too quickly or another component on the SUB board over consuming? Can I disengage the CRT's one at a time on this set to verify that it is not a bad CRT since that is where the issues started?
