Samsung PS-42Q96HD PSU Clicking BN44-00194a DYP-42W2PLUS

[bobby4star]

Hi folks,

I have this TV PS-42Q96HD DYP-42W2PLUS in for repair, PSU is clicking - cycling every 2 seconds. Have checked all caps with esr meter and and replaced a few that were visibly bulged, reading high, and one that had completely failed. With mains applied, psu starts clicking and Vs is measuring at 304 - 306v (too high, should be 205!) With oscilloscope i can see Vs flies up to 300v+ then falls as relays click out, then climbs again. Disconnecting from the panel, with psu on bench, Have added resistors to back of board to force PSU on and Vs on. Vs then sits up at 304v constantly, no relay cycling. Va is at 63v just as it should be. Has anybody seen this issue before with Vs being well over voltage? Anyone have an idea what it may be? I wonder it there is over voltage protection that is kicking in, hence the click cycling? Is it likely to have damaged the y-sus board?

Thanks
Bob

[R_J]

Re: Samsung PS-42Q96HD PSU Clicking BN44-00194a DYP-42W2PLUS

Can you adjust the Vs with VRS401 ? even though the voltage is high does the adjustment work, if not it could be a fault with ics401 reference ic or PCS801 optocoupler

[bobby4star]

Re: Samsung PS-42Q96HD PSU Clicking BN44-00194a DYP-42W2PLUS

Hi, yes i can adjust Vs with the nearby VR, but it is still sat in the 300v range and i can adjust it within a plus / minus ~15v range. Seems an odd fault this one!

Thanks Bob