Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

[Scorpio9]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

ok.... hmmmm..... it would appear based on the first picture that you can see that there is some horizontal lining happen. That usually points to an issue with the side.... but the amount of "disturbance" vertically is somewhat surprising although not necessarily unseen / unforeseen as issues with a side tab can have strange results impacting the lower edge boards at the bottom of the panel that are feeding the side edge boards and ultimately feeding the side tabs which in this case appear to have an issue.

the next check would be to look closer on the side tabs of the likely bad side (left side from the back... since disconnecting it gave a relatively good picture). look to see if the lower tab on that side are hot or have some form of "heat burns". that will confirm that you are on the right track and likely only have to remove that side to get a working set again. This is just for extra care as once you have removed the sides, there is no way back as they CAN NOT be replaced.

Yeah, I know what you mean.... the T-Con boards are rather cheep, now do you think it would be wise to try and get one and give that a shot before I proceed any further if I don't find any burned drivers.

So you find that most of the time the side that shows the best picture it is the opposite side that is normally bad?

I find it a strange that they would have to place the drivers hanging out there on the tabs like that it seems very dubious to me to design it like that though I'm not a EE, however, I have 36 years in electronics service field but I could not find any schematics for this set. In the early 80's I apprenticed in a TV shop but that dried up in 1986 when the price of TVs crashed and shuttered 98% of the service field in a matter of 5 years, everything was gone. But it looks like it might return if we could get parts and service literature, but they don't want that to happen but it should if they really care about this earth we can keep this stuff out of the landfill longer and cut consumption of materials and resources way down. ehhh that's a talk for another day. Thanks for your help it is a very interesting story this thread and your one of the few that do not like to give up that's not something you see much anymore. My hats off too you.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

thanks... I too hate to see stuff head to the dump if it can be save in some reasonable manner.

It is unlikely that you problem is associated with the tcon itself. It is more likely a problem at the edge boards. Your tests show the side that is in trouble. The signals are highly dependent on the characteristic of the path(s) from the tcon to the panel... hence the Timing and CONtrol nature. Changes in these due to failure results in your type of display. BUT it is possible that the issue could be a SMD device on one of the edge boards along the way (ie. a capacitor or resistor) of which there are many. Normally, those fail completely and result in no picture on one side (or totally).

I am pretty sure that your set is some what "classical" in a tab failure but there is no sure thing with "internet troubleshooting" and my eyes and your eyes and tv are miles away. :-)

Lastly, you don't necessarily have to see the issue, you will also likely find with a careful touch of your finger that there is significant temperature difference between the tab drivers which also provide an indication of an issue.

[Scorpio9]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Hay budwich that fixed it had one very thin line on the left side of the set from the top to the bottom. The bottom tab had signs of being warm not like it had totally overheated and burned but you could tell it had a problem. I'm truly impressed even the 3D functions which is why I wanted to save this because this TV belongs to my mother-in-law and she has a few thousand dollars invested in 3D movies and they don't make 3D TVs anymore, so she's pretty happy tonight.

Thanks a million. you saved another one.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

glad it worked out and glad to hear that the 3d function still works.... not sure if any one ever confirmed that the 3d still functions after the "save" but that's great.

[Scorpio9]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

glad it worked out and glad to hear that the 3d function still works.... not sure if any one ever confirmed that the 3d still functions after the "save" but that's great.

Yeah, I looked through the thread pretty hard to see if the 3D would still work and could not find out, so now we know for sure.

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

glad it worked out and glad to hear that the 3d function still works.... not sure if any one ever confirmed that the 3d still functions after the "save" but that's great.

Hey guys, I read through most of this thread and no luck. I have a LC-70LE732U with the 2-5 blinking pattern. The tv belongs to a friend of mine who said initially the screen was showing funny colors etc. Finally, it just stopped turning on. If I plug it into the wall I notice a green light on the main board and a blue light steady light in the front. After a short time the blue light starts throwing the 2-5 code and also notice the green light on the main board turns off (although I believe the unit is still powered on?)

I tried disconnecting the T-con ribbons, doing a reset, changed T-con, main board and power supply but all the same symptoms.

Can someone help point me in the right direction? Thank you in advance!

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

So basically, I am getting no backlight or anything even when the tcon cables are disconnected. I saw someone say that if your tv turns on with the cables disconnected then its a panel issue. So I DO have some hope for this TV :/

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

totally disconnecting the tcon from the panel will likely cause the set to not turn on.
you need to follow a "disconnect one at a time" PLUS you need to do the force on sequence because the error count is likely set to prevent the set from turning on.

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

totally disconnecting the tcon from the panel will likely cause the set to not turn on.
you need to follow a "disconnect one at a time" PLUS you need to do the force on sequence because the error count is likely set to prevent the set from turning on.

Hey bud, first off thank you for all of your help here. Amazing that you took on this project with no real experience yet helped so many saved their sets. Kudos to you for that!

So, I tried unplugged different ribbon cables, etc and nothing. No power, no backlight just the blue light and thats it. When I hold the power button down the blue light on the front of the tv gets brighter for a split second and then turns off.

I even used the volume down + channel up to force it but still nothing. Seems like sometimes the 2-5 code disappears but still no backlight or anything?

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

totally disconnecting the tcon from the panel will likely cause the set to not turn on.
you need to follow a "disconnect one at a time" PLUS you need to do the force on sequence because the error count is likely set to prevent the set from turning on.

From what I can gather right now....

1) I am not getting a 2-5 blink code when the left side edge tab is disconnected. Just a faint blue light in the front of the TV but TV doesn't turn on/ no backlight even when trying to force.

2) Usually the green light on the main board shuts off after a few seconds. A few minutes ago I noticed the green light on the main board blinking slowly and a red light was on one of the ports (some type of input port?) on the main board. Ive never seen activity like this on the main board before.

However still dead tv with no backlight or signs of life to the panel?

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Typo.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

well.... then you need to start checking voltages as listed / printed on the boards usually near or at the connectors. This is done at standby and again at power up.... providing a list of the pins / labels and the measurement will then help point things further.

NOTE: I don't believe that the 2-5 is only a "panel issue" as there can be other things wrong that cause the flash code. One thing you need to verify is the present of 12v at the power supply, again at the tcon and potentially then following that voltage (or equivalent) at the bottom edge boards.

Still further: what cable are you referring to with this "I am not getting a 2-5 blink code when the left side edge tab is disconnected"

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Ok, I also swapped out PSU, Main board, and T-con board with ones i ordered but still same symptoms so I guess its worth a shot to check voltages since I haven't been able to get the tv to turn on at all. Ive never done this before. Is there a document you used accessible online that I could follow for testing the power?

As for the ribbon cable, I am referring to the two on the bottom left/right that plug into those boards on the edge.

[nomoresonys]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Check second link in signature below.

[budwich]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Ok, I also swapped out PSU, Main board, and T-con board with ones i ordered but still same symptoms so I guess its worth a shot to check voltages since I haven't been able to get the tv to turn on at all. Ive never done this before. Is there a document you used accessible online that I could follow for testing the power?

As for the ribbon cable, I am referring to the two on the bottom left/right that plug into those boards on the edge.

ok... those ribbons should have given you the possibility of a picture in some form especially since the flash code disappeared. I am thinking that you have an issue with bottom edge boards... potentially a capacitor or resistor. Lots of posts around that type of failure and some success people have add in tracking down the component and carefully removing / replacing.

Testing for voltage is just a "standard meter test"... nothing special. The labeling on the boards usually indicate what the pin / location is being used for. Once you do those readings as suggested and post, it will provide the forum with a better view of the situation. Some of the pins are "functional signals" while others are "truly just voltages" (ie. 12v, 5v, 3.3v, etc).

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

ok... those ribbons should have given you the possibility of a picture in some form especially since the flash code disappeared. I am thinking that you have an issue with bottom edge boards... potentially a capacitor or resistor. Lots of posts around that type of failure and some success people have add in tracking down the component and carefully removing / replacing.

Testing for voltage is just a "standard meter test"... nothing special. The labeling on the boards usually indicate what the pin / location is being used for. Once you do those readings as suggested and post, it will provide the forum with a better view of the situation. Some of the pins are "functional signals" while others are "truly just voltages" (ie. 12v, 5v, 3.3v, etc).

Hey bud,

Yes, nothing seems to get the screen or back lights turned on at all. I noticed sometimes the green light on the main board cuts off a few seconds after power on and sometimes it'll stay on but blinking. Not sure if this has anything to do with it.

trying to search for posts regarding 'LC-70LE732U bad edge board' but can't find anything. Can you point me to some threads that you know of with a similar issue?

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Also I am getting ready to test the voltage on these pins but they are a bit confusing to me.

Is this the pins I am supposed to test? How do I know which is 1 (beginning) and where it ends? Doesn't seem to be labeled.

[budm]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

PD connector: The exposed pins you see on the top side of the board are the ODD number pins, pin 1 is printed on the left side of the connector, pin 2 is printed right blow. The EVEN number pins you will have to use the skinny probes on the wires entrance of the connector. You can also look at the bottom side of the board, you will see pin 1 and pin 2 markings.

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

PD connector: The exposed pins you see on the top side of the board are the ODD number pins, pin 1 is printed on the left side of the connector, pin 2 is printed right blow. The EVEN number pins you will have to use the skinny probes on the wires entrance of the connector. You can also look at the bottom side of the board, you will see pin 1 and pin 2 markings.

Thank you. Right now the TV is upside down vertically leaning on something so its a bit hard but Ill be following up in a separate post with the readings I got from top to bottom. Thanks again!

[anthony_c]

Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?

Ok, so with ONE side of the edge tab ribbon cable disconnected (the left side) these are the readings on got on this pin. I attached a photo since my TV is currently standing upside down I checked from bottom to top. This is my first time doing this so please forgive me. I have a "auto range" multi meter so I am not sure if it is even giving the correct readings but maybe since you guys have so much experience you can tell if i did something wrong.

The TVs blue light in front was on and steady (no blinking since I did the volume+channel down reset and disconnected the cable.

As I mentioned, even when I disconnect the edge board ribbon cables no luck on getting the TV on so bud suggested it could be some other problem. I also changed the P/S, Tcon and main board but still same symptoms. Im hoping to save this one from being scrapped so any and all help is appreciated!

Please remember the readings are from bottom to top:

8.8v
.659
12.7v
12.5v
5.04v
3.32v
02.2v
02.3v
13.36v
03.6v
11.92v

Thanks again!