The model no: of my LG TV is RF-21 FA20KV.
SMPS is ok.
found h out transistor get short circuited.
i removed transistor; make sure that all supporting components are normal..
insert a new transistor with a new LOT.
Switch on the system with disconnected the Motherboard from CRT etc.
heard "chick" sound and sound of the h out oscillation.
then make all connections . after switch on the system; with in three seconds hout transistor get again short cktd.
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Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis. http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced. To some models of sets, all these section circuit will be integrated at its main board. If this is the case, you have to replace the main board.
When the DC filter caps no longer filter out high frequency AC, that AC will be fed through out the circuits and cause damages such as the inverter frequency will be running at the wrong frequency and caused overheating.
The service manual does not show the sch of the power supply/inverter board because it is not designed by Viewsonic. http://s807.photobucket.com/albums/yy352/budm/Viewsonic%20VX924/
This is typical as the SMPS power supply is shorted when the connector is on to the board. when you remove the connector, the short releases and the power resumes as the SMPS has a high current cut off for protection.
So the easy way out is to have a multimeter and check the power line to the circuit disconnected to check out the shorted driver. Once you have zeroed in to the component release and connect power supply to confirm. Now replace the shorted component.
make sure that any high voltage in circuits are discharged when you use the ohmmeter in the circuit.
If you are referring to the C5707 inverter driver transistors, you can test them in circuit with an ohmmeter. Usually one pair will show shorted although only one may be actually shorted. Normal procedure is to replace the pair that shows in circuit short. If you do not resolder the transformer connections your transistors will short again. Monitor Mike
the horizontal output transistor appears to be short-circuit.
the clicking noise is the SMPS power cycling as it detects a circuit fault.
the real problem here is finding out what killed the HOT, flyback transformer is the usual culprit.
Personally, i'd ditch this monitor. good quality flat screen CRTs can be had for almost nothing these days and the cost to repair this will exceed the cost of a good 2nd hand 21-22" sony/mitsubishi unit
Hope this helps you like what I did to resolve this kinda problem. If you can manage to open the chassis/cover check first if the HOT (horizontal output transistor) is good, if good check the SMPS (switching mode power supply) primary and secondary side if there are short filter capacitors, diodes, transistors and open resistors. Major faults to consider is by checking the load of SMPS, control circuit, driver circuit, feedback ckt.
Please let somebody to assist you (a certified technician) how to open the chassis safely due to electric shock. Please be guided accordingly.