Vizio E701i-A3 no Picture

[bjorkson]

Re: Vizio E701i-A3 no Picture

Yeah, if your TCON does not fix the issue, only other problem i see is a defective panel or the EEPROM on the main board.

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Good call

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Wow I just went to Target earlier today and I found the 70 and 60 inch model still on sale. Same exact model number. The 70 inch was working perfect but the 60-inch had a small horizontal Black line going to the screen but still working.

[tom66]

Re: Vizio E701i-A3 no Picture

Wouldn't surprise me, many of these LCDs with Sharp panels seem to have huge reliability issues. Until last year, Sharp was the exclusive supplier of 60"+ panels as no other manufacturer had mass-production capability. That's since changed, especially as Samsung etc have moved into curved TVs (now I bet those are fun to repair...)

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Yeah its funny you mention that because before 2014 it seemed that sharp panels had good reliability. Well the panels anyway not so much to say about the LED backlighting but now that other manufacturers are starting a mass produce bigger size panels sharp might have cheap and on their manufacturing processes just to keep up. I have yet to see a true sharp curved lcd panel yet.
I wouldn't be surprised if this panel was built in China or Mexico. But I'm still reluctant to say the panel is at fault because I have no low voltage going to the gamma processor and the core voltage supplied to the main processor on the tcon board. I can monitor the 1.2 volts try to come up but immediately fell as soon as I turn the TV on. This is on a brand new t-con board that's never been met to the panel yet. Same goes for the old t-con board that supposedly went out while the person was watching it

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Can anyone confirm NPN mosfet with the label COXA ? The only thing I have found is a CO5A 60v 5a npn. These short center pin to right pin on these tcons when the problem arises. Also I should note there is no power going to this transistor at all either.

[budm]

Re: Vizio E701i-A3 no Picture

MOSFET is either N -CH or P-CH. Bipolar Junction Transisor is NPN or PNP.
So what do you have?

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Sorry. I meant NPN transistor marking COXA. It's a 3 pin small smd SOT-23 casing

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Okay I got my replacement t-con board tonight same problem however I notice between pin one and three of the Coxa transistor I had 523 ohms after I connected it to the main board nothing I had no pictures still but now its 1.2 ohms between the pi s. Also I should note that on the new board the transistor marking is COPA

Also I recently scavenge parts out of a broken screen Philips 55 inch LCD TV that used to sharp panel so I have is tcon board. The connectors are different on the output but I was able to verify that the main board is producing 12 volts and the T CON board is getting 3.3 1.2 and 15 volts. So clearly the mainboard must be fine.

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Found the transistor and found a cross reference. Didn't do anything

http://m.aliexpress.com/item/32378541068.html

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Ok so now it looks like the other two small SOT-23 transistors on the DC converter circuits are open thus not supplying power to the rest of the board.

[CapLeaker]

Re: Vizio E701i-A3 no Picture

Since there is a lot of folks reading this thread, maybe good if you could add a picture so others know what components you are talking about.

[freakaftr8]

Re: Vizio E701i-A3 no Picture

This pic was posted earlier by another user. The one in red is the transistor that shorts. The other two SOT -23 style in the pic seem to go open.

[electronics60]

Re: Vizio E701i-A3 no Picture

Hello everyone,

Need some help or assistance please on a Vizio E701i-A3. Working on one where the power comes on using either remote or side panel power button. When power on, the backlight comes on and stays on, just no picture. I suspect it's a bad T-con board model RUNTK5261TP-ZH. When I measured the F101 fuse, label (5A @32V), getting less than 1 V. I suspect it to be bad. So, I order one off of Ebay and put in in. No change, still getting the backlight on, no picture. But with the new tcon board in there. I am getting a 12.32V reading, but not the 32V. Is it supposed to be a full 32V for the picture to come on? Did I buy a bad Tcon board? Can anyone please advised. Thanks in advance.

I have tried replacing the T-con boards on many of the 70" & 60" VIZIO with no luck I know it is the panel . I finally figured out how to repair the panel , I have done 5 of the "70 and 4 of the 60" VIZIO.

[electronics60]

Re: Vizio E701i-A3 no Picture

You could also disconnect one of the ribbon cables going to the T-con board one at a time and figure out which side of the panel is shorted you should be able to get half of a picture depending on which side is shorted.

[Moroccansoul85]

Re: Vizio E701i-A3 no Picture

Hello! And how did you figured out how to repair the panels?

[freakaftr8]

Re: Vizio E701i-A3 no Picture

Here you go for your reading pleasure.

https://www.badcaps.net/forum/showthread.php?t=49281

And

https://www.badcaps.net/forum/showthread.php?t=48477

Trial and error.

[kingstv]

Re: Vizio E701i-A3 no Picture

I have tried replacing the T-con boards on many of the 70" & 60" VIZIO with no luck I know it is the panel . I finally figured out how to repair the panel , I have done 5 of the "70 and 4 of the 60" VIZIO.

Would you please tell me how to repair the panel on the 70"? I have tried replacing all boards to no avail, still no picture. (I got a deal on all 3 boards). I'm about to take it out back and

[kingstv]

Re: Vizio E701i-A3 no Picture

You could also disconnect one of the ribbon cables going to the T-con board one at a time and figure out which side of the panel is shorted you should be able to get half of a picture depending on which side is shorted.

Is your method the same as Freaks?

[Blessed]

Re: Vizio E701i-A3 no Picture

I have tried replacing the T-con boards on many of the 70" & 60" VIZIO with no luck I know it is the panel . I finally figured out how to repair the panel , I have done 5 of the "70 and 4 of the 60" VIZIO.

Could you post where and how you fixed your pannel?