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

[Diah]

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

check again yours soldering work that no short between pins...
remove the dimmer jumper they will flash again
wait for yours MB.

[beetle1303]

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

These SHAPRs have bad contacts (connectors) on the LED strips (you need to solder them)

So I re-soldered all the pins of L1 and L2 connectors.

Some of the pins has got tiny bubbles when heated up, not sure if those are signs of bad contact?

But now it doesn't flash at all... Value of OFL changed from 1.74V to 0.8V, all others remain the same.

[Diah]

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

the mystery deepens, lol.

good points... OP need to dive deep to see whats going on this second blink..

[nomoresonys]

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

the mystery deepens, lol.

[Diah]

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

at this moment i wouldn't care of this since PD-22 (ERROR) =0 V mean no error.
MB signal are not only V. its pules freq. we can see there are several pins need signal..

i never read some one successfully to run the BL on at this PCB all are one click.. one things more this BL had nothings to do with main fault.. because MB just one signal send PS_ON no other signal as the cpu communication failed.

[lotas]

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

These SHAPRs have bad contacts (connectors) on the LED strips (you need to solder them)

[beetle1303]

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

With jumper wires on:
PD-15 (BU5V) ----- 14 PS_ON ( turn on UR13.2V )
PD-15 (BU5V) ----- 16 PNL_POW (turn on PNL12V )
PD-15 (BU5V) ----- 24 (STB) ( turn on BL_ on ) IC7700
PD-15 (BU5V) ----- 21 OFL
*PD-15 (BU5V) ----- 19 Dimmer (983ohm resistor)


PD Connector:
PD-1 (PNL12V) : 11.92V
PD-2 (PNL12V) : 11.92V
PD-3 (SGRN) : 0V
PD-4 (SGRN) : 0V
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) : 4.55V**
PD-20 (NC) : 0.04V
*PD-21 (OFL) : 1.74V*
PD-22 (ERROR) : 0V
PD-23 (NC) : 0.04V
PD-24 (SBY) : 4.3V

Added PD-15 to PD-19 with 983ohm resistor and read 4.55V, and value of PD21 changed from 0V to 1.74V.
Still the same - screen flashes for a split second then off.

[nomoresonys]

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

add one on dimmer and see what you get. You beat me by a second Diah, that's what I get for using too many words.

[Diah]

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

you forget dimmer

[nomoresonys]

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

850 should be fine.

[nomoresonys]

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

ok, then i think it is what was suspected bad led/s.

[beetle1303]

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

The PD-21 (OFL) must also be fed through a 1 kOm 5v resistor.
Yes, and all command pins must be supplied with 5v (standbay) through 1 kOm resistors.

ith jumper wires on:
PD-15 (BU5V) ----- 14 PS_ON ( turn on UR13.2V )
PD-15 (BU5V) ----- 16 PNL_POW (turn on PNL12V )
PD-15 (BU5V) ----- 24 (STB) ( turn on BL_ on ) IC7700
*PD-15 (BU5V) ----- 21 OFL*


PD Connector:
PD-1 (PNL12V) : 11.92V
PD-2 (PNL12V) : 11.92V
PD-3 (SGRN) : 0V
PD-4 (SGRN) : 0V
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) : 0V
PD-20 (NC) : 0.04V
*PD-21 (OFL) : 0V*
PD-22 (ERROR) : 0V
PD-23 (NC) : 0.04V
PD-24 (SBY) : 4.3V

Now the screen Flash in split second then off.

*BTW all jump wire with ~850ohm resistor - it this OK?

[Diah]

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

OFL and dimmer should be feed too from PD-15 (BU5V) .
use 1K R to avoid the mosfet of BL circuit overload.

[nomoresonys]

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

so 14, 16, 24, ofl, if no joy hook up dimm also.

[nomoresonys]

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

I think you need to hook up the dim too, try it both ways maybe.

[lotas]

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

The PD-21 (OFL) must also be fed through a 1 kOm 5v resistor.
Yes, and all command pins must be supplied with 5v (standbay) through 1 kOm resistors.

[beetle1303]

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

so now it clear.
to complete pcb to run as standalone

PD-15 (BU5V) ----- 14 PS_ON ( turn on UR13.2V )
PD-15 (BU5V) ----- 16 PNL_POW (turn on PNL12V )
PD-15 (BU5V) ----- 24 (STB) ( turn on BL_ on ) IC7700
------------------------------------------------------
PD-21 (OFL) = DIM (low / high )

With jumper wires on:
PD-15 (BU5V) ----- 14 PS_ON ( turn on UR13.2V )
PD-15 (BU5V) ----- 16 PNL_POW (turn on PNL12V )
PD-15 (BU5V) ----- 24 (STB) ( turn on BL_ on ) IC7700

PD Connector:
PD-1 (PNL12V) : 11.92V
PD-2 (PNL12V) : 11.92V
PD-3 (SGRN) : 0V
PD-4 (SGRN) : 0V
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) : 0V
PD-20 (NC) : 0.04V
PD-21 (OFL) : 0.14V
PD-22 (ERROR) : 0V
PD-23 (NC) : 0.04V
PD-24 (SBY) : 4.3V

But, still no backlight on...

I measured again the big cap all has 400V, but the feed to the 2 big transformers input pins all still showing 0V..
I did a bit of guess tracing - is transformer T7703 input voltage coming from the secondary side to provide output voltage in the primary side to feed the gate of the transistor Q7700 & Q7701? I traced the 400V from caps to left pin of Q7700, but no voltage on its center pin.

[Diah]

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

so now it clear.
to complete pcb to run as standalone

PD-15 (BU5V) ----- 14 PS_ON ( turn on UR13.2V )
PD-15 (BU5V) ----- 16 PNL_POW (turn on PNL12V )
PD-15 (BU5V) ----- 24 (STB) ( turn on BL_ on ) IC7700
------------------------------------------------------
PD-21 (OFL) = DIM (low / high )

[lotas]

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

OFL is DIM, Try to run a PSU with backlight without a motherboard, there are 3 or 4 signals for on, 1kΩ resistor and 5v duty. (OFL for backlight too)

[Diah]

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

I found this page from one of the link provided interesting and will be very useful if the replacement MB doesn't fire-up the backlight.

all these are working at your PCB other wise you will not have 13 / 12V. only we didnt test the BL circuit because for me i cant figure it out where are the signal to turn it on,,, so i wrote let the MB do the job first,

can you follow the pathof OFL line and dimming one too from downside the PCB?