petehall347
06-05-2012, 04:04 PM
first of hello i am new here .i am regularly on audiokarma though :D
ok i have a bush lcd27tv005 . thing is no back-lights they just flash on and straight off at start-up .i have checked the 24v supply to the inverter board it measures 23.6v . is it high enough ?
i haven't checked the other voltages to inverter board yet as i don't know what they should be or if they should be checked with a scope ?
i am just trying to determine if it is a inverter problem or not before i order a new board for it .
petehall347
06-06-2012, 07:12 AM
well i am surprised no one can help me on this just yet . maybe i am being impatient ? or i am just used to audiokarma and its fast flow of things mmm ..no rush really i just like to get things working and back together so i have room for the next jobs .
Zenith26kc20
06-06-2012, 10:37 AM
I've never heard of a Bush LCD. Have you looked for bulged capacitors on the power supply board? This is the biggest cause of LCD TV failure. Can you post a picture of the insides of the set?
You may want to search "capacitor plague" for more info.
petehall347
06-06-2012, 03:04 PM
yes checked the caps they look good but haven't cap tested them . i have fixed lots with new caps ..i am thinking if its not the inverter it could be a problem on the main board as that's what's switches the lights on . i need to know what voltage to expect on the pins that switch the inverter on .
all fuses test good including 0 ohm resistors .all diodes test good .
i could just buy a new inverter board to see if it fixes it but i would be stuck with it if it wasn't the problem
Zenith26kc20
06-06-2012, 04:00 PM
Some LCD tv's are marked on the board and depending on the main board it sends either a high or a low to the inverter boards when the set is turned on. Can you see who actually made this set?
petehall347
06-06-2012, 05:26 PM
ok i have checked the switch on pulse it is 5v for split second . i think the boards are Chinese .
will get pics as soon as i can .
i am thinking it has to be bad inverter board component now maybe bad chip ?