e701i-a3 no picture but backlights

[cueballsi]

Re: e701i-a3 no picture but backlights

here is a tip. in a dark room, boot up the TV. If you see the screen V flash, then that means it is an LED issue. IF an LED shorts out on a strip, it will take out the whole strip (like xmas lights). IF you want to tackle this job, be very carful when removing the Lcd... If that cracks, Bye Felica!

Once you get the LCD screen and diffusers off... turn on your phone camera to high speed and boot up the tv.... you will see the LEDs light up on boot up ... and the surge of power will arch through the bad LEDs. your high speed video will capture this, and you can determine which ones are dimmer/not lighting in the video... those are the bad LEDs.

I learned all this on youtube :-)

NOW- replacing the LEDs ... you tube that... they use a heat gun type soldering iron.

I have an E701i-A3E that went black while watching it a few months ago, sound still works and image is still on screen after flashlight test. When the TV powers on the V logo and the backlights do appear for maybe a half second, then it goes black, sometimes with a slight flickering. replaced the tcon and nothing, replaced the power board and had the exact same issue. finally i took the plunge and removed the screen to find that this is actually an edge lit TV with 3 led strips along the bottom of the screen, which i did not expect. upon further review i was able to find at least 2 burned out LEDS in one of the 3 led strips. this problem to me did not seem at first to be bad leds since the backlights were coming on and then flickering and turning off. the flickering caused me to believe it was power supply related. however it would seem this model was released after the backlit led model and from what i have gathered the power supply on this TV will cut all power to the backlights if it detects any of them being bad. this particular issue, with this particular model is very hard to find any info on. i am not a pro and just like to do this in my spare time, so if this can help anyone i would be happy. good day to all and if anyone knows what the part number for these led strips are, it would help, as i cannot see a clear part number on the strips themselves. or maybe a little help as to where to find the part number, thanks.

[cueballsi]

Re: e701i-a3 no picture but backlights

Well need some help guys... i removed the drivers and put it all together have some lines.. I think I need to clean the cables and put them back. BUT I noticed the following:

- I used a OO power cable instead of the [ ]O looking power cable to power up the tv.
- The LEDs seem to brighten and darken and brighten like a very slow strobe.

Did I mess up the board with the power cable? I switched to the [ ]O type and still slowly pulses....

what would make the LEDs do this?

any help would be appreciated. What should I test? Will the shop Jimmy Referb power board kit fix this?

[kevinm34232]

Re: e701i-a3 no picture but backlights

You need to replace the bad LEDs or the whole strip. The power supply will shut down to protect from over voltage.

[BOOSKI00]

Re: e701i-a3 no picture but backlights

I have an E701i-A3E that went black while watching it a few months ago, sound still works and image is still on screen after flashlight test. When the TV powers on the V logo and the backlights do appear for maybe a half second, then it goes black, sometimes with a slight flickering. replaced the tcon and nothing, replaced the power board and had the exact same issue. finally i took the plunge and removed the screen to find that this is actually an edge lit TV with 3 led strips along the bottom of the screen, which i did not expect. upon further review i was able to find at least 2 burned out LEDS in one of the 3 led strips. this problem to me did not seem at first to be bad leds since the backlights were coming on and then flickering and turning off. the flickering caused me to believe it was power supply related. however it would seem this model was released after the backlit led model and from what i have gathered the power supply on this TV will cut all power to the backlights if it detects any of them being bad. this particular issue, with this particular model is very hard to find any info on. i am not a pro and just like to do this in my spare time, so if this can help anyone i would be happy. good day to all and if anyone knows what the part number for these led strips are, it would help, as i cannot see a clear part number on the strips themselves. or maybe a little help as to where to find the part number, thanks.

[cueballsi]

Re: e701i-a3 no picture but backlights

OKAY got the TV going to dig into it tomorrow and test some resistances on the TCON board.

SYMPTOMS- has back light, no image, 2 or 3 bright white spots at the bottom

I found these videos:

How to test Mosfet:
https://youtu.be/yTnkOfwBGGE

How to tell you how to determine which side of the panel is bad:
https://www.youtube.com/watch?v=cyCKoMi_5IA

How to remove the Ribbon:
https://www.youtube.com/watch?v=sJ0EzOuckyU

[cueballsi]

Re: e701i-a3 no picture but backlights

I am suppose to be getting a free E701i-A3 on monday. we will see... I read a majority of the posts, and the you tube video helped quite a bit. Once i pick it up I will order the transistors (RTR020N05TL)... 5 pcs from digikey for $9.10.

the owner sad they were watching it and one day while watching it went blank... and he believes it still had sound...

I just re did some LEDs on a E60-C3, so this one will be interesting... will be back once I have it and get pics

[budwich]

Re: e701i-a3 no picture but backlights

:-( well double check the side area down in the lower part of the screen. Its a big tv and it can be tough to manipulate during your work so lots of things can go wrong.

Another test you can try to see if things improve.... at the bottom of the panel, each "half of the panel", has a pair of edge boards. They are connected together with "U" type ribbon cables which a "unclampable" much like the tcon to panel cables are. Unclamp the "U" cable and see what happens (of course, do cable manipulations in an unpowered state.

[culcuhain]

Re: e701i-a3 no picture but backlights

Thank you for the quick responses! The small corner cable and the driver boards are removed from the left side (facing screen)of the tv. I take the bezel back off and look real close at the panel there.

[budwich]

Re: e701i-a3 no picture but backlights

could be .... without seeing what you actually have done, I have to take your word that you did as good a job as your "cable seating" was... :-) potentially some issue at the bottom corner of the panel on the side you removed. Did you leave the small corner cable in place on the side that you removed the tabs from?

[culcuhain]

Re: e701i-a3 no picture but backlights

ensure that your cables are properly aligned / seated.

Doh! Did that and now the picture is perfect (several little tiny little white spots though) except the the bottom of the. See attached pic. Looks like I didn't do the tabs clean enough?

[budwich]

Re: e701i-a3 no picture but backlights

ensure that your cables are properly aligned / seated.

[culcuhain]

Re: e701i-a3 no picture but backlights

Good afternoon!
E701i-A3E. Powers on. Has Backlights. No video. I pulled the T-con and tested the FET and it is shorted. I have 10 replacements. I replaced it. Powered on the TV. the V shows up and left side facing the screen is dark. Then back to the no picture dealio. Ok. Left side facing has issues. Removed the T-con and replaced the FET. I removed the left side tabs from the panel. Now I have the V, then the no signal, but it has lines in it. See attached pic. Need to check my tab removal or T-con has other issues?

[nomoresonys]

Re: e701i-a3 no picture but backlights

I have performed same fix and picture came back. I watched tv for about 2 months and yesterday on the bottom of the screen thin horizontal line appeared. See photos. Line does change colors every once in a while. When i was removing tabls I removed completely board and ribbon cable tabs and they came off nice and clean. I am not sure what is happening with this line now. Is maybe place where i cut off ribbons shorted between those microwires? Is there board on other side of screen and what would taking off of those boards do (opposite side of screen)?

After doing fix suggested here tv was good but once i an a while i would notice tiny picture flicker but noone else noticed it. Anyone has any suggestions ? Thanks

Not sure what you mean here BUT if you mean strip the tabs off BOTH sides of the tv THAT would trash it, you need them in tact on the good side whichever it is or the tv will not work.

[budwich]

Re: e701i-a3 no picture but backlights

the "fix" that you likely performed is to fix the card.... but the reason the card (component on the card) blew was because of the issue with the panel which the line on the panel shows. This will eventually take out the card component again. You need to remove the tabs on the bad side also for the tv to be completely saved.

[gavric]

Re: e701i-a3 no picture but backlights

I have performed same fix and picture came back. I watched tv for about 2 months and yesterday on the bottom of the screen thin horizontal line appeared. See photos. Line does change colors every once in a while. When i was removing tabls I removed completely board and ribbon cable tabs and they came off nice and clean. I am not sure what is happening with this line now. Is maybe place where i cut off ribbons shorted between those microwires? Is there board on other side of screen and what would taking off of those boards do (opposite side of screen)?

After doing fix suggested here tv was good but once i an a while i would notice tiny picture flicker but noone else noticed it. Anyone has any suggestions ? Thanks

[eeq067]

Re: e701i-a3 no picture but backlights

Can't tell from the pictures, what is your result one half good picture and other half distorted or horizontal lines running thru it? and you tried unplugging both ribbon cables from tcon to panel one at a time right? (always with tv unplugged from power) when unhooking cables.

Yes. Sorry for the bad pics. Removed the right side driver tabs, but part of it didn't come off cleanly. I'm slowly cleaning the residue off. Currently there is a section in the middle with some short horizontal colored lines,

[nomoresonys]

Re: e701i-a3 no picture but backlights

Can't tell from the pictures, what is your result one half good picture and other half distorted or horizontal lines running thru it? and you tried unplugging both ribbon cables from tcon to panel one at a time right? (always with tv unplugged from power) when unhooking cables.

[eeq067]

Re: e701i-a3 no picture but backlights

I was given a tv with this same problem. I replaced the tcon board and disconnected the ribbon cable connecting the driver board on the right(from the front) side. My results are attached. Going to attemp to remove the right driver tabs. I'll share my results for any still facing the problem.

[jtcurtis]

Re: e701i-a3 no picture but backlights

Removed bottom left ribbon cable to drivers and this is what I have. Anyone know if this is a bad left side driver? Haven't tried other side but can you tell by the picture? Dark pic in middle and I'm not sure if panel is bad.

[jtcurtis]

Re: e701i-a3 no picture but backlights

Thanks to all for creating this informative site. I've read through most all of it and a little confused about checking the lcd panel from the tconn diode. I have a reading of 9.6 ohms with bed both ribbons connected. Is that telling me I have a good LCD panel because my transistor is certainly questionable has no reading on bolts DC?