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

Hmm, I don't have a heat gun.. Is a 2000w big hair-dryer good enough? Or a small butane torch safe for this?

Nope.. with the big 2200w hairdryer at max heat min for 6-8min, nothing happens..

[beetle1303]

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

so the BGA issue at main IC became more.. use hotair gun to toast the mediateck chip only... who knows could catch solder point.

Hmm, I don't have a heat gun.. Is a 2000w big hair-dryer good enough? Or a small butane torch safe for this?

[Diah]

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

Baking in oven at 250C 12min, off oven open door slight to cool for 20min, took out and cooled to room temperature. Man, it stink!!
And when able to get power up 2x flashing red light, did all the reset procedures: Vol- & Chn-, Vol+ & Chn-, etc. all the results are no difference from those before back, including those voltages when reset to green led light.

so the BGA issue at main IC became more.. use hotair gun to toast the mediateck chip only... who knows could catch solder point.

[beetle1303]

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

1) Screen ribbon cable unplugged from T-Con, power on normal - no change flashing 2x red flight
2) While screen ribbon cable unplugged, pressed Vol- & Chn-, powered up: no change flashing 2x red light.

Will do the oven bake tomorrow morning, then redo these various procedures.
Thank you, and good night.

Baking in oven at 250C 12min, off oven open door slight to cool for 20min, took out and cooled to room temperature. Man, it stink!!

All the white plastic connector turned brown... I think the PD connector deformed and not able to get a tight-fit clicked connection anymore.
Seems like intermittently connection problem now. On powered up -the power indicator 2x flashing sometime there sometime not. After a few hard reseat, it eventually failed and not able to get power up indicator anymore...

And when able to get power up 2x flashing red light, did all the reset procedures: Vol- & Chn-, Vol+ & Chn-, etc. all the results are no difference from those before back, including those voltages when reset to green led light.

So, I guess the MB is truly toasted, time to move on the get a replacement MB now.

[Diah]

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

okay. seriously.. let finish here
when we are testing PCB standalone and we did have the main V 12 or 13 0r 24 v. these are what MB need so we stop testing standalone , we leave it to MB to see first step starting ( eeprom ) sending PS_ON if it did and main V we find them which i mentioned before are enough
any lack of other Panel or BL are because Main IC don't give feed back signal to eeprom so it stay blind didnt send signal to turn them on..... this is 99,9% the case over all TV platform.

[Diah]

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

indeed that is reasonable, I wouldn't be surprised if the mainboard is the only problem, .

you are now indeed join my 2 glass whisky with me lol

[nomoresonys]

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

indeed that is reasonable, I wouldn't be surprised if the mainboard is the only problem, interesting thread, will be watching, I own a sharp lc from 2007 but it never broke, hope it don't, I don't get much opportunity to fiddle with a sharp. Seem to be good tvs tho except for the ones with the panel problems.

[Diah]

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

I just have a hard time believing that both boards went out at the same time, that IS very rare.

dear friends.
we did with him standalone test for PCB and we do have all what we need pnl_12 ok main 13V ok. so we dont care on others,, because the threat you linked his MB was able to torn BL and other,, here are some things ells.

i asked him on messure while he had green LED at front and it was as i thought SPI send power on and we do have 13V but panel 12 v. and BL was out.. so if the main CPU ( mediateck) didnt response the SPI will be blind and wiuld never turn PNL_12 or BL on. so here we are.. his MB toasted why i dont know.. but am sure you agree with me.. that we avoid other make other damage to PCB at time we approved it respose to PS_ON... or.....

cheers.

[nomoresonys]

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

I just have a hard time believing that both boards went out at the same time, that IS very rare.

[nomoresonys]

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

well here's another thread that eludes to a powerboard problem, note he gets the same readings of voltages, yet there is a fault, so you can not be too quick to dismiss the powerboard as the fault: https://www.badcaps.net/forum/showthread.php?t=56629

[nomoresonys]

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

well ya got to fix everything that is broken, good main bad power still equals broke tv, there evidently is a problem with the backlights or the powerboard, because he can not force on the backlights.

[beetle1303]

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

okay... do this first

unplug the screen ribbon cable from the T-CON and power on normal. see result
keep panel unpluged and use volume - channel - see the result
on both we are interset on BL if it come on. and PNL_12 had 12V.
if all didnt help do this
put every things back and use input and volume + see the result

if all didnt bring different... time to use hot air gun to 280° to cook the mediatech chip in case it had BGA issue... or packing your MB in oven for 10 minute in same degree but with out using air flew, just the up and down with out air. when temp reach high put the board inside and dont move it after backing time untill it cool down. good luck

1) Screen ribbon cable unplugged from T-Con, power on normal - no change flashing 2x red flight
2) While screen ribbon cable unplugged, pressed Vol- & Chn-, powered up: no change flashing 2x red light.

Will do the oven bake tomorrow morning, then redo these various procedures.
Thank you, and good night.

[Diah]

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

okay... do this first

unplug the screen ribbon cable from the T-CON and power on normal. see result
keep panel unpluged and use volume - channel - see the result
on both we are interset on BL if it come on. and PNL_12 had 12V.
if all didnt help do this
put every things back and use input and volume + see the result

if all didnt bring different... time to use hot air gun to 280° to cook the mediatech chip in case it had BGA issue... or packing your MB in oven for 10 minute in same degree but with out using air flew, just the up and down with out air. when temp reach high put the board inside and dont move it after backing time untill it cool down. good luck

[beetle1303]

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

okay, then with volume+ channel - when you have green LED messure the sockets on PCB which voltage you have on it.

With the PS mounted onto TV, I can only probe the odd pins:
PD-1 (PNL12V) : 0V
PD-3 (SGRN) : 0V
PD-5 (UR13.2V) : 13.05V
PD-7 (UR13.2V) : 13.05V
PD-9 (SGRN) : 0V
PD-11 (SGRN) : 0V
PD-13 (AC_DET) : 3.27V
PD-15 (BU5V) : 4.95V
PD-17 (NC) : 0.04V
PD-19 (DIMMER) : 0V
PD-21 (OFL) : 0V
PD-23 (NC) : 0.04V

[Diah]

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

Input & Vol- no effect, same 2x flashing red light.

okay, then with volume+ channel - when you have green LED messure the sockets on PCB which voltage you have on it.

[beetle1303]

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

eeprom OK
CPU main IC no communication to let eeprom confirm to turn on the screen and BL

try input and vloume -

Input & Vol- no effect, same 2x flashing red light.

[Diah]

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

Better!!
Vol+ & Chn- turn the power indicator stationary green! After 10-15 seconds, release the buttons, still stationary green but black screen..

Press power button will turn off and turn on the green light, but when it's off there is no red standby light.

Also, when power off from the wall socket, it will turn back to 2x flashing red light.

eeprom OK
CPU main IC no communication to let eeprom confirm to turn on the screen and BL

try input and vloume -

[beetle1303]

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

try volume + channel -

Better!!
Vol+ & Chn- turn the power indicator stationary green! After 10-15 seconds, release the buttons, still stationary green but black screen..

Press power button will turn off and turn on the green light, but when it's off there is no red standby light.

Also, when power off from the wall socket, it will turn back to 2x flashing red light.

[Diah]

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

Repeated VOL- & CH- procedure several times, no effect - blank screen, and power indicator started green, then flashing red 2x, constantly.

try volume + channel -

[beetle1303]

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

leave it.... do the following to force the tv power on and reset fault in case there are error at BL

remove all jumpers.. and plug every things as original. plug the tv out from wall socket.

While holding down the “VOL (-)” and “CH ( - /down)” keys on the set at once, plug in the AC power cord to turn on the power.
After a central icon flash off, separate the fingers from key on the set.
Then, you can check the operation to see if the lamp and lamp circuit are in trouble.
If you fail boot-up, retry the procedure.

page 44 service manual

Repeated VOL- & CH- procedure several times, no effect - blank screen, and power indicator started green, then flashing red 2x, constantly.