Hi Guys,
I need your expertise with repairing my TV power supply board, I'm trying to find the issue with the standby circuit, ATM i don't have any 5v STBY and 4.3V PS-ON coming to CN801 i.e nothing on the cold side.
i follow the hot side DC voltage from the BR>PFC>Filter Caps>STBY Transformer via ICE3BR2565JF flyback circuit and i'm getting 330V on the hot side of the transformer. i also get 330 volts coming in to one of the ICE3BR2565JF pins.
when checking the other pins on the ICE3BR2565JF i don't get any 18v coming in from the ICE3BR2565JF flyback circuit to start the ICE3BR2565JF. So i have a good feeling that the issue is the ICE3BR2565JF but this area was covered in silicon, when removed i found few faulty components such as CX895, DX859 and damaged printed circuit which i soldered wire, also DQ804 is a suspect, see attached images.
ICE3BR2565JF can be download from this link
https://www.infineon.com/dgdl/Datasheet_ICE3BR2565JF_v20_11Sep08.pdf?folderId=db3a304412b407950112b4182a3d24f8&fileId=db3a30431ce5fb52011cf40f584204eathe problem now is as follows:
1. as i don't have the diagram to find out the part numbers so i can't order the DQ804, CX895 and DX859
2. I cant follow the damaged printed circuit as there are black marking covering it, so i can't confirm the path to fix.
Is there any way to find out the part numbers and the damaged circuit path of the above without the diagram?
Till now i have tested and replaced with new ones all the following:
1. All the CAPs on the board (except the HV Hot and cold big filter caps)
2. DS810 small signal diode BAV70
3. QS802 & QS804 Switching Fets
4. Tested all the main diode, DQ804 was measuring 0.200v when all the others UF4007 was measuring 0.500v
FYI i just started a month ago learning basic electronics (very late stage ),SMPS Circuits as a hobby and knowledge, i'M building up my LAB equipment ATM.
Thank you for your help.
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