Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ
maybe try heating those looks like 6 electrolytic caps there by the connector on powerboard with a hairdryer, turn on and see if it does anything different, can you trace the ofl from connector to one of those caps, maybe one of them isn't up to par, what voltages are you getting on them with powerboard jumped?
maybe try heating those looks like 6 electrolytic caps there by the connector on powerboard with a hairdryer, turn on and see if it does anything different, can you trace the ofl from connector to one of those caps, maybe one of them isn't up to par, what voltages are you getting on them with powerboard jumped?
I have earlier measures the capacitance of these caps, and all are on-par with the stated values. But I dont have the meter for ESR values.
On powered-up with jumped pins, all these caps measured between 5-13+V, looks quite normal to me.
What might not be normal is the T7901 - similar to T7701 & T7702, it measures mostly 0V on the input and output pin-pairs.
What is the correct way to measure transformer in put and output voltages?
Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ
you should be getting voltage on some of those, on hot side you use the negative of one of the big filter caps as ground, so neg. probe on that and pos. probe on what you're checking.
Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ
power boards are fine...
yours problem at MB, didn't send PS_ON... could be the MB tosted / dead or the SW or too the SPI flash.
the front LED when it blink its the first boot sequences of the SPI which it didn't complete... try freeze the SPI
if you still have no voltage when powered, maybe trace it to where it stops, which seems to be right after the big caps somewhere in that area.
I am not getting any voltages on those 2 transformers. And you're right, after tracing the 400Vdc from the big caps to the component Q7700, and 0v output to the transformer.
I tested this transistor:
1) Red probe on middle pin:
Black probe on either pin - Open
2) Black probe on middle pin:
Red probe on left pin: 528
Red probe on right pin: 732
power boards are fine...
yours problem at MB, didn't send PS_ON... could be the MB toasted / dead or the SW or too the SPI flash.
the front LED when it blink its the first boot sequences of the SPI which it didn't complete... try freeze the SPI
I am very convinced MB is completed toasted, since there is any shorts that causing fluctuating voltages like it was initially.
But I also curious about whether the BL is working since it has no power to he BL section of the PS.
From my precedent replying post - does it looks like BL is not working?
I am not getting any voltages on those 2 transformers. And you're right, after tracing the 400Vdc from the big caps to the component Q7700, and 0v output to the transformer.
I tested this transistor:
1) Red probe on middle pin:
Black probe on either pin - Open
2) Black probe on middle pin:
Red probe on left pin: 528
Red probe on right pin: 732
Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ
men... you are really funny... who care on BL if they come on or not when the MB dead.
did you know which pin BL_ON ?? we tested panel 12V. and main 13V are good mean PCB 100% working
what the diffrent if man his legs brocken and you insist to teach him dancing !!!!
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