Hi ,
thanks for pdf
pictures of board attached , i know the connector doesnt look sat in socket properly but i removed it and didnt put it back fully for photo
all tests were made with the connector in fully.
i was thinking of disconnecting the stby pin wire to measure the voltage on it then and see what it reads
is the voltage on the stby (ps_on) pin generated from the main board ?
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Last edited by piccy; 05-19-2015, 09:03 AM.
Reason: missing info
Just split the stby wire from the main board to the psu , with it disconnected from the psu i get 2.36v if i connect the wire to the psu it falls to 1.71v
deducting from that i guess the fault is on the psu side (unless the stby voltage should be higher than 2.36v )
removing the 24v connector makes no difference, removing the 12 connections may be more difficult
can i somehow put 3v onto the stby pin from say the 5v supply ?
just tried opening the pdf you posted there is just a link to a website , i will follow that
What you can do is to leave off the STBY wire going back to the main board first, then use 300~1K resistor between the STBY pin of the power supply and the 5VSB pin of the power supply to force on the power supply. The DCV between the two legs of the main filter cap (450VDC) should jump up from 330VDC to >360VDC (PFC Voltage booster is turned on), this boosted voltage is needed for the 12V/24V power supply to run.
Hi Budm,
tried putting resistor across from 5v rail ,this put 3v onto stby pin voltage across main filter cap 317v before linking with resistor no increase after putting link in place so not sure where to go from here i will check the components in the circuit that the standby wire comes into theres a resistor diode and cap in there along with some optos
ok,
have you access to the schematic ? the link i followed doesnt show anything different to the one you posted (no drawing) , will also have a read of the links you posted to articles have read the basic troubleshooting one , will look at the regulator info
looking at the drawing most of which i need to figure out and is going to have me scratching my head but am i right in thinking pfc controller ic is U601 ?
Hi Budm
have measured voltage on u601 across pins 6 and 8 and i get 15.1v , i have connected the main board feed and it still reads 15.1v so i can presume the feed from the main board is sufficient to operate it , if i put the set in standby then the 15.1v disapears as you would expect.
just done a few checks round the pc501 opto on pin 1 i get 5.24v on stby and when remote pressed this drops to 1.4v suggesting to me that the transistor is being switched on
as a follow on presuming from that the opto is working as the supply vcc to ic601 is derived from this opto switching on , and having just realised from looking at the circuit i answered my own question (idiot) from the first comments above re U601 voltages
as i have no voltage increase on main filter cap and i have voltage to U601 then my checks are going to be around Q601 / Q602 area , is there anything else i may need to check around U601 (in your experience) and what is the best way to test the fet ?
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