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

[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?

[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.

[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?

[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

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

[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

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

With only PD connector on MB, only PD-15 showing 4.96V (and not fluctuating), the rests are 0V... I connected Display and power to T-Con, same readings on PD connector, and everything connected back to MB, still same readings - only PD-15 has 4.96V.

Seems like not connect to MB at all? Or MB is dead?

[beetle1303]

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

put every thimngs back as original. and remove load from the MB , mean speaker socket out wifi module if you have also out.. turn on and check if you have the 13V at start up.. if no you need MB in case your BL are 100% fine.

With only PD cable connected - now the power led indicator flashing 2x red, constantly.
I connected the display & power cables to T-con board - same flashing 2x red light.

I was curious about LED tester show mostly 175V per strip but I didn't see any led light at the back of TV. So I test again and watch the TV screen - no visible light also even though LED Tester show 175V. Possible to have all the led strips shorted?

[Diah]

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

put every thimngs back as original. and remove load from the MB , mean speaker socket out wifi module if you have also out.. turn on and check if you have the 13V at start up.. if no you need MB in case your BL are 100% fine.

[beetle1303]

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

is this DIY TV ??? why the socket which it should be at MB go down and had DIY cable ..

This is the same PS board that we're working on to check if it is working, with all the jumped wires to measure the voltages of PD connector. When mounted back onto the TV, I kept the jumped wires to see if the TV backlight comes on when powered up.

MB metal plate cover removed just to show how cables are connected.

You want to see the PS to MB cable connected?

[Diah]

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

is this DIY TV ??? why the socket which it should be at MB go down and had DIY cable ..

you should put every things back as opriginal so you can troubleshooting the MB .

[beetle1303]

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

yours PCB are fine dont touch it any more.. put it back and show us whole photo of TV back showing how boards connected and photos on your MB and it chassis lable.

Please see attached - TV Back, MB, and Chasis Label.

[Diah]

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

yours PCB are fine dont touch it any more.. put it back and show us whole photo of TV back showing how boards connected and photos on your MB and it chassis lable.

[beetle1303]

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

better scout 2 more then, you will need to jump ps-on, pnl-pow, ofl and dimmer to bu5v, then you can see if the backlights come on and stay on, if they do then your backlights and powerboard are ok.

Jumped PD-15 to PD-14; and PD-16, PD-19, and PD-21, each with a 800ohm resistor:
This is power supply stand-alone, without any connection:
PD-1 (PNL12V) : 11.92V
PD-2 (PNL12V) : 11.92V
PD-3 (SGRN) : 0.02V
PD-4 (SGRN) : 0.02V
PD-5 (UR13.2V) : 13.05V
PD-6 (UR13.2V) : 13.05V
PD-7 (UR13.2V) : 13.05V
PD-8 (UR13.2V) : 13.05V
PD-9 (SGRN) : 0V
PD-10 (SGRN) : 0V
PD-11 (SGRN) : 0V
PD-12 (SGRN) : 0V
PD-13 (AC_DET) : 3.27V
PD-14 (PS_ON) : 4.95V
PD-15 (BU5V) : 4.95V
PD-16 (PNL_POW) : 4.58V
PD-17 (NC) : 0.04V
PD-18 (NC) : 0.04V
PD-19 (DIMMER) : 1.34V
PD-20 (NC) : 0.04V
PD-21 (OFL) : 1.64V
PD-22 (ERROR) : 0.12V
PD-23 (NC) : 0.04V
PD-24 (SBY) : 0.01V

Opto-couplers 1: input: 0.99V / output: 2.78V
Opto-couplers 2: input: 1.08V / output: 0.14V
Opto-couplers 3: input: 0.15V / output: 0.84V

Mounted PS back onto TV, connected LED backlights, powered-on, but nothing happens - no backlight on TV...

A quick checked - the big cap shows 403Vdv but all the transformers above it shows no voltages in all the output pins... With a LED tester - all the 14 led strips are mostly 175V, with 2-3 showing 173-174V.

What/where else to check?

[nomoresonys]

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

better scout 2 more then, you will need to jump ps-on, pnl-pow, ofl and dimmer to bu5v, then you can see if the backlights come on and stay on, if they do then your backlights and powerboard are ok.

[beetle1303]

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

good so we do have 13V. ur PCB okay... now you add another jumper use R1K from pin 15 to pin 16 PNL_POW to turn on PNL12V.

Alright!
But got to go scout for the R1K resistor from the stashed PCBs. It's passed midnight, will do this tomorrow morning and report back.

Thank you.

[Diah]

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

Jumped PD-15 to PD-14:
This is power supply stand-alone, without any connection:
PD-1 (PNL12V) : 0.01V
PD-2 (PNL12V) : 0.01V
PD-3 (SGRN) : 0.01V
PD-4 (SGRN) : 0.01V
PD-5 (UR13.2V) : 13.05V
PD-6 (UR13.2V) : 13.05V
PD-7 (UR13.2V) : 13.05V
PD-8 (UR13.2V) : 13.05V
PD-9 (SGRN) : 0.01V
PD-10 (SGRN) : 0.01V
PD-11 (SGRN) : 0.01V
PD-12 (SGRN) : 0.01V
PD-13 (AC_DET) : 3.27V
PD-14 (PS_ON) : 4.95V
PD-15 (BU5V) : 4.95V
PD-16 (PNL_POW) : 0.11V
PD-17 (NC) : 0V
PD-18 (NC) : 0V
PD-19 (DIMMER) : 0V
PD-20 (NC) : 0V
PD-21 (OFL) : 0V
PD-22 (ERROR) : 0.12V
PD-23 (NC) : 0V
PD-24 (SBY) : 0.1V

Opto-couplers 1: input: 0.99V / output: 2.78V
Opto-couplers 2: input: 1.08V / output: 0.14V
Opto-couplers 3: input: 0.15V / output: 0.84V

good so we do have 13V. ur PCB okay... now you add another jumper use R1K from pin 15 to pin 16 PNL_POW to turn on PNL12V.

[beetle1303]

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

check D7951 diode.

D7951 diode:
In-circuit: forward: 318 reverse: 1568
Off-circuit: forward 310 reverse: open

[nomoresonys]

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

check D7951 diode.