e701i-a3 no picture but backlights

[freakaftr8]

Re: e701i-a3 no picture but backlights

RTR020N05

You can get it from Mouser.

1st do an ohms test reading against all 3 legs. Read my original post and you will find out how to test this one

[constantine1000]

Re: e701i-a3 no picture but backlights

Somebody could tell me if these method works for E65-C3

[freakaftr8]

Re: e701i-a3 no picture but backlights

The method yes possibly but tcon board is different does not use this particular voltage divide circuit, Even though it uses a a Thine PWM. Probably safe to say that T con will survive a short

[ivoh]

Re: e701i-a3 no picture but backlights

Hello, I recently picked up a e601i-a3 with no picture, went through the basics and all voltages on psu seem fine, backlight seems fine, turns on and off fine, tested tcon board for blown coya mosfet and it was fine on my set, tested resistance between the cathode side of diode and ground as i saw in a video and got 10k ohm (video claimed 1k: panel is bad, 10k:panel is good) fuse on tcon not blown, tcon gets 12v.

I bench tested my tcon with a current limited 12v supply, and it pulls about 200ma with no panel connected, and i found 12v, 15v, 33v, 1.3v, and 3.3v all present just poking around the tcon. suspecting eeprom corruption now, since repair kits for this tcon include coya mosfet and the eeprom. Anyone have a eeprom bin dump so i can compare to mine? this is runtk5261tpzc tcon version.

Any other things anyone can suggest, id rather find the issue and do component level repair rather than hope a new tcon fixes it. Thank!!!!

[ivoh]

Re: e701i-a3 no picture but backlights

Can someone confirm if a RUNTK5261TPZG tcon board can be used in place of a RUNTK5261TPZC, i can find the G revision for much cheaper to where id buy one to see if it fixes it. For the e601i model.

[Boltz.]

Re: e701i-a3 no picture but backlights

RTR020N05

You can get it from Mouser.

1st do an ohms test reading against all 3 legs. Read my original post and you will find out how to test this one

I didn't really understand the ohms test so I didn't perform that but I kept trucking along.

They were out of stock at Mouser so I bought them from ebay (RTR020N05TL model specifically).

When I tested the new board I bought for ~$70 I had the right side unplugged and had no change in picture. I replaced the transistors on both my factory board and the new one that I just fried. Plugged in the original board only the LVDS cable and tested it, voltages looked good!

This time I tested with the right side plugged back in and the left side removed and voila! The V came up - Turned it off instantly to be safe and then reread the thread for the millionth time to make sure I'm not being a dummy since this is the non-reversible step. Once I made sure I wasn't crazy I peeled off the tabs on the left side (did it carefully but they pulled off clean), plugged the TV back in and HOLY CRAP IT WORKS!

I bought this TV in 2013 from Costco, it blew in 2015, 1 month after my warranty was up. I found this thread in 2015 and started taking the TV apart then stopped the process when I realized I might end up blowing through a bunch of Tcon boards. I had some time recently to clear up some old projects and was surprised to see you still active in this thread!

Thanks for taking the time to help everyone else and me. Can I paypal you some money to buy yourself a 6-pack?

[freakaftr8]

Re: e701i-a3 no picture but backlights

No worries bud that's what we're here for! Glad to hear it's finally up and running.

[ivoh]

Re: e701i-a3 no picture but backlights

Can someone confirm if a RUNTK5261TPZG tcon board can be used in place of a RUNTK5261TPZC, i can find the G revision for much cheaper to where id buy one to see if it fixes it. For the e601i model.

I bought one and tried it. Still no picture. The transistor on the new board is not shorted either, i bought it as a used board. Does anyone have any suggestiond what else to try, is it because i used the G tcon in place of my C? Bad main board?

[freakaftr8]

Re: e701i-a3 no picture but backlights

Should not be a big deal I imagine. However if you're ever in doubt you can use an upgraded Tcon. The Sony KDL-70r550a tcon will work with this panel and it does not have the same inherent bad design.

On your TV there is a slight possibility that the mainboard is not sending the signal

[budwich]

Re: e701i-a3 no picture but backlights

did you actually try any of the "cable disconnect tests" that everyone else has tried to see what the results were?

[ivoh]

Re: e701i-a3 no picture but backlights

I tried disconnecting just the cables from the tcon to the panel, i would just get a white side and a black side when i disconnect one of them, alternating if i switch which is disconnected. On the e601i the ribion cables for the horizontal drivers are buried in the panel assembly and a pain to get to so i havent tried that yet. Whats the bandwidth for lvds data? Ive got a dso138, maybe i can see if the main board is sending lvds data. Tomorrow Im planning on reading the eeprom from the ZG tcon and comparing it to the ZC tcon. Maybe ill try to load the ZG bin onto the ZC. Any other suggestions are welcome. Ill probably try reflowing the main cpu if i can determain the mainboard is not sending image data.

[budwich]

Re: e701i-a3 no picture but backlights

ok... were you feeding a signal in? did you try pressing menu to see if anything gets displayed during the "cable disconnect test"? doesn't sound good with what you have seen / done so far. it would appear that you have a rather unusual fault.

[ivoh]

Re: e701i-a3 no picture but backlights

ok... were you feeding a signal in? did you try pressing menu to see if anything gets displayed during the "cable disconnect test"? doesn't sound good with what you have seen / done so far. it would appear that you have a rather unusual fault.

I dont get a v or anything else on startup, nothing comes up when pressing any button on tv or remote. Backlight starts dim when power is pressed and goes to full brightness after a few seconds.

Another thing i noticed, it didnt want to turn on in the cold, it was 19f last night and its in my unheated garage and it didnt turn on this morning until i warmed the boards a bit with a heater, although that may be unrelated or it could be indicative of maybe bad solder joints on the main board? Or drying caps? Although all the voltage rails seemed present and stable when i checked them.

Another thing i noticed is the new tcon board reads 15v 2.3v and 0v on the suspect transistor, where as the old on was 15v 3.3v 0v.

Ill see what else i come up with tomorrow, likely culprits at this point seem main board, panel failed but not shorted?, or faulty ribbon cables.

[driveallnight]

Re: e701i-a3 no picture but backlights

Hi Freak, I too just fixed my Vizio E701i-A3E by following your excellent instructions for diagnosing and removing the bad driver boards (mine happened to be the front left side). Thank you!

[ivoh]

Re: e701i-a3 no picture but backlights

I tested my tempurature theory today, indeed when the main board is cold the tv will not start up. I put the main board in ther freezer and tried to start the tv, no power on when the main board was at 27f. I warmed it to 88f and the tv turned on. Im wondering if it's safe to assume that the main board is also the cause of the no picture? Thanks for any suggestions. Ill keep testing in the mean time

[freakaftr8]

Re: e701i-a3 no picture but backlights

I tested my tempurature theory today, indeed when the main board is cold the tv will not start up. I put the main board in ther freezer and tried to start the tv, no power on when the main board was at 27f. I warmed it to 88f and the tv turned on. Im wondering if it's safe to assume that the main board is also the cause of the no picture? Thanks for any suggestions. Ill keep testing in the mean time

That board should not have a temperature coefficient problem. I would expect problems with your tcon.

I would look at the conditions of your LVDS cable. Do the wiggle test while the T con is connected to the panel. When the TV is on wiggle the LVDS connector in-and-out of its socket very gently and see if you get flickers or lines across the screen

[budwich]

Re: e701i-a3 no picture but backlights

you can try and direct some "hair dyer heat" at small sections (as possible) while trying to turn on the set (after colding it) to see if you can detect which area is more susceptible to temperature issues.

[ivoh]

Re: e701i-a3 no picture but backlights

So i tested the tempurature more in depth, indeed the main cpu seemed to have tempurature issues and most likely bad bga connections. I removed the heat sheild, and blasting the cpu with freeze spray would result in the set not powering on when plugged in until i warmed the cpu and replugged power. When the set was in its unresponsive state, the power board was being turned on by the main board, all rails besides backlight and tcon were on, the main cpu seems to lock up when its too cold and leave the power supply in a semi turned on state.

Additionally something i should have tried a long time ago, none of the hdmi inputs would get recognized by my laptop, and since they go straight to the main cpu that further concludes that that's likely the fault.

I did clean and reseat all the tcon/panel related cables when i got the set and didnt see any trouble there.

Im gonna look around for a cheap mainboard on ebay in the next week or so, i think any revision from a e601i-a3 should fit unless someone can state otherwise?

[sman200788]

Re: e701i-a3 no picture but backlights

Recycled to me by a customer that was told it was not repairable!

Left side driver failure here!

I am blown away that I was able to fix this thing!!! What is the estimated life of these after repair? Ill be pulling my 55" down and hanging this 70" tonight

[freakaftr8]

Re: e701i-a3 no picture but backlights

Nice. 6 mos to ?? I've had one failure but every other 1 that I've done that I know it still works 3 years later