e701i-a3 no picture but backlights

[budwich]

Re: e701i-a3 no picture but backlights

none... :-) :-(

[Alexbry1981]

Re: e701i-a3 no picture but backlights

So by reading this thread it seems like this may be my issue. I'm new to all this...so here's my current situation...no image, do have backlights, installed a new tcon board, tv worked for about 10 secs and then screen went dark again. What are the chances the new tcon board isnt fried?

[bradzke]

Re: e701i-a3 no picture but backlights

Changed a bad MOSFET. Got a partial picture with the right side disconnected. Removed the tab bonds on that side and now have a functioning 70 inch. Thanks to all for the legwork.

[bradzke]

Re: e701i-a3 no picture but backlights

Just started an account. Going to be working on a E701i-A3.

[Tvbob]

Re: e701i-a3 no picture but backlights

HI all..Looks like you are reducing panel's (native) refresh rate buy 50% when you remove the driver boards. But you are save them from the land fill for now

[evanroheff21]

Re: e701i-a3 no picture but backlights

Has anyone got any of those tiny COXA chips left that they're not using? Bought a T-con board, disconnected the bottom left 3/4 ribbon cable as instructed, got a partial picture (all distorted lines as the TV booted up) powered it off, checked panel resistance on following the video from post #916 or whatever it was, panel seemed to check out as ok on both left and right sides. Plugged it back in carefully and back to just the black lit screen with no booting. Chip on the tcon before installing was reading like 2.1K ohms on the bottom left leg and like 10M ohms on the bottom right leg. Now it's reading like my original t-con with no ohms on the bottom right leg and like 900 ohms on the bottom left leg. I'd gladly pay somebody a couple bucks to mail me some (3 or 4) spares, otherwise I'll just buy that 10-pack from Mouser.

[jackfish]

Re: e701i-a3 no picture but backlights

I just fixed a sharp 70 inch...the tcon is a lot bigger then the sony...maby thats why it didint blow...just removed the tabs on the left side...

[budwich]

Re: e701i-a3 no picture but backlights

I don't see the celebratory beer in the picture although I think I see the "tech" relaxing. :-) Glad to see another save successful. The tv will likely last a long time since the "infancy failure rate component" has already failed... :-)

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

Here are the final pictures. First one is the strobingdorpt and lines running up the right side of screen. Changed out upgraded Tcon and 2 picture is the end result.

[kevinm34232]

Re: e701i-a3 no picture but backlights

Good job!

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

Actually after thinking about it I do plug in the ribbon cable to the tcon so it can power the vertical lines. Correct?
For some reason having a hard time attaching the pictures to this post. I'll keep trying.

Update- I have a perfectly working beast of a TV today!!!! Want to give a big shout out to Freakafter8, Budwich, Kevin and everybody else that figured this workaround fix! Let's how long this works for.
After these pictures I peeled the ribbons off the right side panel, pugged in the ribbon cable into the Tcon, turned on and had lots of colorful vertical lines on the right side of screen. I then cleaned the right side ribbon cable and that helped some but still had some light stoving up that Sid of panel. Cleaned ribbon 3 more times with same strobing. So I changed out the tcon board to the second one I replaced the transistor on. Plugged her in and I HAVE A PERFECT PICTURE!!!

[kevinm34232]

Re: e701i-a3 no picture but backlights

Yes ribbons to T-Con connected, but on the side of the TV with low resistance, disconnect the ribbon in the corner of the panel. Then resistance should be close to same on both sides.

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

Actually after thinking about it I do plug in the ribbon cable to the tcon so it can power the vertical lines. Correct?
For some reason having a hard time attaching the pictures to this post. I’ll keep trying.

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

Alright, new transistor installed right side ribbon disconnected from tcon and also disconnected from right bottom front corner of tv. I will peel the ribbons off the right side front of panel tomorrow. Question tho, after peeling right side ribbon off panel, there is no need to plug in the right side ribbon cable into the tcon board..Correct?

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

Transistors came in today. Just soldered them on board. Gonna re read the test procedures & read post 916 and run my tests. Stand by. Thanks for all you brilliants!! It Boggles my mind how you came up with crazy Fix Feak. If this work which I am pretty sure will, I will be calling this TV Frankenstein which is a freak. LOL

[kevinm34232]

Re: e701i-a3 no picture but backlights

Where exactly are you looking at on the screen? Sorry it was upside down it's just the way it was positioned and I was by myself trying to hold it up and take a pic. On that TV, the right side was bad.

OK that black line on the top lower quarter of the screen. It looks like it extends off darker on the right side. Even though the picture in the post 916 is upside down I would say there something wrong with the right 2nd or 3rd row side tab driver. The middle of the picture in the dark area is mura. This is a clear indication of the panel is not receiving or taking full voltage to the drivers as in they are shorted are loaded down. Should know that even in some repaired situations there's always a dark area in center of the screen. This is because panel is not able to produce full voltage control handled by both sides. Yours is to the extreme though.

[freakaftr8]

Re: e701i-a3 no picture but backlights

OK that black line on the top lower quarter of the screen. It looks like it extends off darker on the right side. Even though the picture in the post 916 is upside down I would say there something wrong with the right 2nd or 3rd row side tab driver. The middle of the picture in the dark area is mura. This is a clear indication of the panel is not receiving or taking full voltage to the drivers as in they are shorted are loaded down. Should know that even in some repaired situations there's always a dark area in center of the screen. This is because panel is not able to produce full voltage control handled by both sides. Yours is to the extreme though.

[budwich]

Re: e701i-a3 no picture but backlights

dirtyphinger, go to post 916 and follow the tests in the video and it appears to take the guess work totally out and save the chance of any further failures on the tcon during the "save" effort trying to identify which side is bad.

[freakaftr8]

Re: e701i-a3 no picture but backlights

My first post exsplains. I replaced the tcon last year. Purchased from eBay for $20. Worked for 15 seconds and died again. It went back to blank screen with back light. Waiting for the transistors now. Hopefully will get em by the weekend

Like I always tell people when you power up the panel on new transistors keep your hand on the plug in briefly notice which side seems darker then immediately unplug it do not keep it running as it will burn the new transistors If you need a few times to do this you can plug it in powered up in immediately unplug it after you can see I say you have about a good 3 seconds

[Dirtyphinger]

Re: e701i-a3 no picture but backlights

My first post exsplains. I replaced the tcon last year. Purchased from eBay for $20. Worked for 15 seconds and died again. It went back to blank screen with back light. Waiting for the transistors now. Hopefully will get em by the weekend