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

[nomoresonys]

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

Did you try the VOL up CHANNEL down while plugging in, see if tv comes up in service menu then see if there are any lamp errors if you get to that clear the errors if any. Looks like you did vol - channel+.

[budwich]

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!

not to "rain on your effort", but you need to make it easy for the forum by providing a good chart of what is happening... not making the forum trying to work across picture, lists and otherwise.

chart doesn't have to be pretty... pin number, label, measurement.

from your testing during this work (soild blue front light) is good. It means that the set can be "forced on". The bad news is that you should have seen backlights come up / on. Did you have an input going, can you hear sound?

[budm]

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

https://www.badcaps.net/forum/attach...8&d=1563917022
That is not pin 1, pin 1 is printed right on the board next to the connector, you can also see pin 2, which you cannot get to it from the top side of the board as I explained).
There are 24 pins total, the connector has to be in place to take the measurement.'
Right now what you report is not usable, no pin name to go along with each pin, wrong pin count, etc.

[anthony_c]

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

Did you try the VOL up CHANNEL down while plugging in, see if tv comes up in service menu then see if there are any lamp errors if you get to that clear the errors if any. Looks like you did vol - channel+.

Hey yes, excuse the typo but I tried it over a dozen times and no go. It does get rid of the blinking if I unplug one side ribbon cable but still no picture.

[anthony_c]

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

https://www.badcaps.net/forum/attach...8&d=1563917022
That is not pin 1, pin 1 is printed right on the board next to the connector, you can also see pin 2, which you cannot get to it from the top side of the board as I explained).
There are 24 pins total, the connector has to be in place to take the measurement.'
Right now what you report is not usable, no pin name to go along with each pin, wrong pin count, etc.

Hey guys, I'm sorry.. I just don't understand how to read the pins on the board correctly since im new to this its a bit confusing to me.

Basically the TV is upside down and I don't want to move it around too much risking a crack in the screen. Not trying to be lazy but I added that picture and labeled It pin 1 to let you guys know where I started with the measurements so:

8.8v - pin 1 (not physically pin 1, but where I marked it on the picture)
.659 - pin 2
12.7v - pin 3
12.5v - pin 4
5.04v - pin 5
3.32v - pin 6
02.2v - pin 7
02.3v - pin 8
13.36v - pin 9
03.6v -pin 10
11.92v - pin 11

If I have to do it all over, that's fine I just am not too sure where to start :/

[anthony_c]

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

not to "rain on your effort", but you need to make it easy for the forum by providing a good chart of what is happening... not making the forum trying to work across picture, lists and otherwise.

chart doesn't have to be pretty... pin number, label, measurement.

from your testing during this work (soild blue front light) is good. It means that the set can be "forced on". The bad news is that you should have seen backlights come up / on. Did you have an input going, can you hear sound?

No problem, I figured I may have done it incorrectly :X

Since I can't see anything or can't even tell what input the tv is on I have no way of testing for sound. I tried playing with the input button to hopefully switch it to an input that'll have sound and nothing.

[anthony_c]

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

Edit

[budm]

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

Hey guys, I'm sorry.. I just don't understand how to read the pins on the board correctly since im new to this its a bit confusing to me.

Basically the TV is upside down and I don't want to move it around too much risking a crack in the screen. Not trying to be lazy but I added that picture and labeled It pin 1 to let you guys know where I started with the measurements so:

8.8v - pin 1 (not physically pin 1, but where I marked it on the picture)
.659 - pin 2
12.7v - pin 3
12.5v - pin 4
5.04v - pin 5
3.32v - pin 6
02.2v - pin 7
02.3v - pin 8
13.36v - pin 9
03.6v -pin 10
11.92v - pin 11

If I have to do it all over, that's fine I just am not too sure where to start :/

Nope, do it all over, pin 1 is printed right on the board, you can see it. Your pin 1 is actually pin 23 if you count the pin correctl.
This is is the format we are looking for:
Pin 1, PNL_12V: XX.V reading
Pin 2, PNL_12V: XXX.V reading
The chart for the PDC connector is printed right on the board, and report the readings for all those pins as listed. BTW, the PD connector has two rows, odd row and even row, 12 pins for each row, so 24 pins total.
I am too lazy to superimpose your pin number to the actual pin, beside you only show 11 pins instead of 12 Pins total for the ODD number pins that you can see from the top side of the board, you did not report any reading for the EVEN number pins (12 pins). Pull PD connector out and you will see how many pins it has. Bad data does not help in troubleshooting.

[anthony_c]

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

Nope, do it all over, pin 1 is printed right on the board, you can see it. Your pin 1 is actually pin 23 if you count the pin correctl.
This is is the format we are looking for:
Pin 1, PNL_12V: XX.V reading
Pin 2, PNL_12V: XXX.V reading
The chart for the PDC connector is printed right on the board, and report the readings for all those pins as listed. BTW, the PD connector has two rows, odd row and even row, 12 pins for each row, so 24 pins total.
I am too lazy to superimpose your pin number to the actual pin, beside you only show 11 pins instead of 12 Pins total for the ODD number pins that you can see from the top side of the board, you did not report any reading for the EVEN number pins (12 pins). Pull PD connector out and you will see how many pins it has. Bad data does not help in troubleshooting.

Ok, I just reread your first post to me and realized my mistake. I was so confused cause I didn't realize the wires were another 12 set of pins :X Also is there a PIN #3? I don't see anything in the legend for that pin #.

I attached a photo here, I think this looks right now?

Also, I am supposed to be testing ONLY with the TV powered on right? And ground probe goes anywhere on the Chasis?

Hopefully all of this will help any newbs like myself in the future, heh

[anthony_c]

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

Nope, do it all over, pin 1 is printed right on the board, you can see it. Your pin 1 is actually pin 23 if you count the pin correctl.
This is is the format we are looking for:
Pin 1, PNL_12V: XX.V reading
Pin 2, PNL_12V: XXX.V reading
The chart for the PDC connector is printed right on the board, and report the readings for all those pins as listed. BTW, the PD connector has two rows, odd row and even row, 12 pins for each row, so 24 pins total.
I am too lazy to superimpose your pin number to the actual pin, beside you only show 11 pins instead of 12 Pins total for the ODD number pins that you can see from the top side of the board, you did not report any reading for the EVEN number pins (12 pins). Pull PD connector out and you will see how many pins it has. Bad data does not help in troubleshooting.

Ok, so I redid it and tried my best. The multi-meter I have has this 'auto range' thing so the numbers go up and down sometimes. Also the EVEN side was bit hard as my probes are somewhat thick but I retested 3 times. Here's what I got the following:

Pin 1, PNL_12V: 11.91v
Pin 2, PNL_12V: 11.94v
Pin 3, GROUND: 0.28v
Pin 4, GROUND: 0.27v (although ground, just posting my meter reading)
Pin 5, UR13.2v: 13.35v
PIN 6, UR13.2v: 13v
PIN 7, UR13.2v: 13.35v
PIN 8, UR13.2v: 13v
PIN 9, GROUND: 02.4v (again, just posting my auto range meter reading)
PIN 10, GROUND: 02.3v
PIN 11, GROUND: 02.3v
PIN 12, GROUND: 0.23v
PIN 13, AC_DET: 3.3v
PIN 14, PS_ON: 3.3v
PIN 15, BU5v: 5.04v
PIN 16, PNL_POW: 5v
PIN 17, PWM1: 13.3v
PIN 18, NC: 13.4v
PIN 19, DIMMER: 13.4v
PIN 20, ?: 13.6v
PIN 21, OFL: 3.4v
PIN 22, ERROR: This pin I tested a few times goes up and down 3v, 5v, 7v in no order. Basically bounces around.
PIN 23, PWM2 / NC?: 9.5v
PIN 24, STB: 9.5v

[nomoresonys]

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

Did you try, with tv unplugged from mains/outlet, unplug cable from powerboard to mainboard plug tv back in mains, see if backlights come on.

[budwich]

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

Ok, so I redid it and tried my best. The multi-meter I have has this 'auto range' thing so the numbers go up and down sometimes. Also the EVEN side was bit hard as my probes are somewhat thick but I retested 3 times. Here's what I got the following:

Pin 1, PNL_12V: 11.91v
Pin 2, PNL_12V: 11.94v
Pin 3, GROUND: 0.28v
Pin 4, GROUND: 0.27v (although ground, just posting my meter reading)
Pin 5, UR13.2v: 13.35v
PIN 6, UR13.2v: 13v
PIN 7, UR13.2v: 13.35v
PIN 8, UR13.2v: 13v
PIN 9, GROUND: 02.4v (again, just posting my auto range meter reading)
PIN 10, GROUND: 02.3v
PIN 11, GROUND: 02.3v
PIN 12, GROUND: 0.23v
PIN 13, AC_DET: 3.3v
PIN 14, PS_ON: 3.3v
PIN 15, BU5v: 5.04v
PIN 16, PNL_POW: 5v
PIN 17, PWM1: 13.3v
PIN 18, NC: 13.4v
PIN 19, DIMMER: 13.4v
PIN 20, ?: 13.6v
PIN 21, OFL: 3.4v
PIN 22, ERROR: This pin I tested a few times goes up and down 3v, 5v, 7v in no order. Basically bounces around.
PIN 23, PWM2 / NC?: 9.5v
PIN 24, STB: 9.5v

that's better. so if I read right, you appear to have major differences in the grounds ...note some are indicate .2ish while others are 2.ish. They should all be roughly the same... but potentially "finger problems". What are you using for your ground reference point for your meter... hopefully NOT one of the labels... usually a chassis screw is used. Further, "ground" as labelled should be checked WITHOUT power on and use your ground reference point (ie. known ground) and measure the resistance from the labeled pin... it should be a "short" / 0 resistance.

the error pin shouldn't be bouncing around, but again it depends on what you were using as a reference ground.... if the "reference" is not truly a ground then it is likely some voltage measurements maybe erroneous but the reference point might be "floating a bit".

Now that you have the "hang of it", there are usually other voltages to worry about associated with powering / driving the back lights. Look at or around the connector that may be coming off the power board and going somewhere up into the top of the panel somewhere.

A picture of the back of the set showing everything connected might help.

[budm]

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

It looks like the board/s screws are not tightened so the board GND points are not making good contact with the chassis, GND pins on the connector should be 0V, your reading show some GND has 0.28v, some have 2.3V so that is not right.
"PIN 24, STB: 9.5v" that does not look right either.
You may not have good connection between your probe tips and what you are trying to measure.

[anthony_c]

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

Did you try, with tv unplugged from mains/outlet, unplug cable from powerboard to mainboard plug tv back in mains, see if backlights come on.

Yep, tried this multiple times. Using an extension cord which is basically the same thing.

[anthony_c]

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

It looks like the board/s screws are not tightened so the board GND points are not making good contact with the chassis, GND pins on the connector should be 0V, your reading show some GND has 0.28v, some have 2.3V so that is not right.
"PIN 24, STB: 9.5v" that does not look right either.
You may not have good connection between your probe tips and what you are trying to measure.

Hey, thanks for the response. yes, I am using the chasis as a ground. My meter is kind of weird I don't really understand it but it could be the auto range feature on it. I'll recheck those pins. I believe STB is definitely showing 9.5v

I'm uploading pictures of the set now.

[anthony_c]

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

It looks like the board/s screws are not tightened so the board GND points are not making good contact with the chassis, GND pins on the connector should be 0V, your reading show some GND has 0.28v, some have 2.3V so that is not right.
"PIN 24, STB: 9.5v" that does not look right either.
You may not have good connection between your probe tips and what you are trying to measure.

Here you go.

[budwich]

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

the top two connectors likely go to powering the backlights... there should be some labeling such as + / - ... you can carefully measure voltage across those "pairs"... note, it might only be momentarily on as the system may shut down those voltage when an error is detected.

Further as mentioned by budm, IF indeed that measurement is correct, it would seem high... maybe. The "ground" measurement seem very strange. Do you have your meter set on DC or AC? Another general check, find two chassis screws locations and measure the voltage across those.... is there a difference? Further, again with power off / disconnected, do the same test with a resistance reading... it should be 0 or a short.

[nomoresonys]

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

Yep, tried this multiple times. Using an extension cord which is basically the same thing.

Extension cord?????

[NautilusComputer]

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

Howdy folks! First post here.

I recently had opportunity to pick up a Vizio E70i-A3E for the low, LOW price of free - problem is, it's got sound and backlight, but no picture. So down the road of 'new mainboard' I started to go...and ran across a post on AVS Forum that had a link to here. As you folks still seem active, I figured I'd check in here first.

If the T-con is blown, will I still be able to unplug the corner cable and test which side is bad, or will I need to have a working T-con first?

Thanks in advance!

[budwich]

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

nope... the "fet" on the tcon blows on vizios as opposed to the sharp design which seems to shut down the set before the tcon dies. You need to go to the "big" vizio thread on here and read about the repair / replacement most do to get the set back up and running.
Because it is a 50 - 50 chance of choosing the wrong side, most have spare components so they can test using the "remove the corner cable" twice to determine which side is bad. You can also visual inspect the side tabs to see if you notice a problem which will help with the guessing.