Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

not sure but OFL seems low, could it be a voltage regulator on mainboard?

[beetle1303]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

not sure but OFL seems low, could it be a voltage regulator on mainboard?

The OFL value is jumped from PD-15 (4.96V) with a ~800ohm resistor, not connected to MB.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

my bad, I missed that it wasn't connected to anything in post 13.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

T7701 and T7702 have been known to be a problem on these models, maybe check them closely.

[nomoresonys]

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?

[beetle1303]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

T7701 and T7702 have been known to be a problem on these models, maybe check them closely.

I am not sure how accurately I checked. With DMM in Ohm mode, both input and output side measures 1-2 ohms only. Both T7701 & T7702 the same.

When powered-up with jumped PD cable, the reads 0V on input pin-pair, and 0V on output pin-pairs.

[beetle1303]

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?

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?

[nomoresonys]

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.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

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.

[Diah]

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

[beetle1303]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

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

Does it sounds bad or OK?

[beetle1303]

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 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?

Question: What's a SPI ?

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

wondering why the backlights didn't come on when powerboard is jumped, sure seems like they should.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

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

Does it sounds bad or OK?

.

[beetle1303]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

wondering why the backlights didn't come on when powerboard is jumped, sure seems like they should.

There is no power supply to those 2 transformers, because Q7700 is either faulty or not triggered?

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

test q7700 again, put black probe on neg. of big cap and red probe on each leg of that fet.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

make sure your meter is set to at least 200 if it isn't an auto range meter.

[nomoresonys]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

what happened? beer break?

[beetle1303]

Re: Sharp LED TV flashing green 2x per second - LC-70LE735X, DPS-222BP, RUNTKA857WJQZ

what happened? beer break?

Black probe on big cap negative, red on middle pin of Q7700 - 402VDC
Black probe on big cap negative, red on either pin of Q7700 - 0VDC

Repeated a few times..

How does this Q7700 works?

[Diah]

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 !!!!