Good day. I have a led screen. 42 ”mark Dw (I guess it is daewoo) the detail is that the screen is dead does not give standby LED. When disassembling and checking the source I see that it does not send the necessary voltage to activate it. Perform the test to disconnect everything except the LEDs and you can see what flashes within 5-8 sec. Check that the source will take out the 5 volts to be able to activate The source on the work table and when checking it it only takes 2.7 v and at the moment it drops to 1.50 and vice versa, check the fat filter and only take 175 v. Somebody could help me

If the stby is low, you must start there, check the stby circuit, in the secondary verify the diodes of the circuit, optocoupler and 431, if possible replace the latter, on the primary side verify the supply of the occulator, resistance, filter, diode and resistance of auto start, comment on progress to continue helping. Greetings and luck