Sharp 70" model LC-70LE733U 2-5 blinks

[ga70gto]

First let me say thank you to this board for helping me fix several Panasonic Plasmas and a Sony Bravia 46" .

Once again another 70" Sharp Aquos Quattron with no picture, no sound with the 2/5 blink code. Using the reset procedure ( hold volume down and input while plugging in) the code goes away until you hit the power button. This occurs whether you have the left tcon cable disconnected, the right tcon cable disconnected or both disconnected. At no time do you get any kind of picture.

I have already replaced the power board RDENCA442WJQZ and T-CON board RUNTK4910TP and the code still remains. Why did I replace these boards? because when you don't exactly know what you're doing it's easier to throw parts at something than actually trying to diagnose it properly so once again I'm asking for this forums knowledge.

I've noticed unlike other Sharp 70" models that have 4 cables at the base of the t-con board mine only has two. Does this change the diagnostic procedures? Like many others I've found little to no technical info about this tv on the net.

As always your help is appreciated.

Pete

[dskall]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Backlights? Power to t-con? Need to post some voltages in this format.

P201

NC. - PWM-DIM :1.14V
BRI :3.4V - ERROR :1.14V
NC. - INV ON/OFF :5V
24V :25.17V - 24V :25.18V
GND - GND
12V :11.87V - 12V :11.87
GND - GND
5V :5.12V - 5V :5.12V
5V :5.12V - 5V :5.12V
GND - GND
GND - GND
NC. - POWER ON :5.04V

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

dskall, thanks for replying.

At no time have I ever seen any backlights nor does the trick of shining a light at the screen seem to reveal anything.

Now, about your post. You seem to indicate connector "P201" but I haven't found a connector with that label or any pins that seemed to be labeled with the descriptions you list.

can you offer a shove in the right direction? thanks for your patience,

Pete

[budwich]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

there are lots of threads for sharp 70 in sets. You basically need to follow those and do some "disconnects" of the corner cables to see if the set responds. This will help narrow down what the issue might be.

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

thanks budwich,

I had read several of those but each seem to contain a four cable tcon instead of the two cable tcon that's in mine. if memory serves the front frame has to be removed to access those corner connectors. I'll have to construct some type of stand to support the tv because it is currently laying down. The tv had been wall mounted previously so no stand was available.

[budwich]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

the tcon cables are not relevant. the corner cables are accessed from the back. re-read some of those thread and look at the pictures. It isn't a sure thing but it might help get "there" sooner.

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Budwich, I reread your post of the 70" sharp you were able to save by removing the tab bonds. In that post you showed a very clear picture of what I considered to be the right lower portion of the tv (with the tv facing down). In that picture the flat cables you referenced can clearly be seen. Attached are two pics, your pic and a pic of my right lower area. On my tv the flat cables cannot be seen and so I'll have to figure out another way to diagnose this tv.

thanks for your patience,
Pete

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

I have been able to make these voltage checks. On the center power board at pin 16 of connector "PD" I have apprx. 3.3 DC volts.

On the tcon board at connector P4804 at pin 1 I have 12 volts. These were achieved by using the reset procedure and remain until the tv goes into the 2/5 mode again.

[budwich]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

those cables are not visible without further disassembly of the lower "chassis". You need to be able to get the lower / bottom edge boards. Further, disconnection of interconnects on the lower edge boards will also help point out things (ie. there are brown clamp on cables connecting the lower edge board ... usually two boards per "half").

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Oh ok , so you have the complete back off where the LED's are located.

pete

[budwich]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

nope... there is some frame items that can be removed covering the edge boards.

back up a bit. what happens when you disconnect one side of the tcon.... then repeat on the other side.

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

my tcon board only has two lower cables and whether I disconnect the left or right or both when I power on the tv using the reset procedure it eventually reverts to the blink code of 2/5.

Attached are pics of the right lower corner of my tv and a picture of the edge, to me it just doesn't look the same as yours.

as always thanks for your time and input,


Pete

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Continuing on with voltage checks of connector PD of the power supply board "before" the tv begins to blink 2/5. This is just with the tv plugged in because it will begin to blink 2/5 without turning it on.

1. PNL12V 12.16v
2. PNL12V 12.16
3. SGND 0v
4. SGND 0v
5. UR13V 13.24v
6. UR13V 13.24v
7. UR13v 13.24v
8. UR13v 13.24v
9. SGND 0v
10. SGND 0v
11. SGND 0v
12. SGND 0v
13. AC_DET 3.30v
14. PS_ON 2.86v
15. BU5V 5.11v
16. PNL-POW 3.33v
17. VSYNC 0v
18. SCL 3.27v
19. NC 0v
20. SDA 3.27v
21. OFL 2.99v
22.ERROR 3.33v
23. NC 0v
24. STB 0v


I don't know if this helps anyone but i'm trying on this end.

thanks for your time and patience,

pete

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Well, well, well......persistence has paid off, or starting to. I removed the entire front bezel/surround and a brace that ran the entire height of the tv but finally found the bottom corner cable and it is NOT white on my tv as the picture shows, making it different from the TV's I've seen posted on here so far, maybe this will help someone else. We'll see what happens in the next few days.....

pete

[Davi.p]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

If you search well you'll find something.. according to this:
http://www.service-manual.net/ashop/...=catalogue.php
you can find SM's on elektrotanya, search f.ex.: LC-70LE732U then...
report the normal PD connec. voltages, or only the ones with a difference, you are following a strange path to troubleshoot, you've changed PSU and TCON, so if you like swapping change also MAIN, if your budget low, check voltage adapters on the main...
just to begin..

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Update***update***update

Although not as satisfying as fixing it yourself I decided to send my mainboard to a company that repairs the boards or has the ability to check yours and see if it's working properly. If it's working properly the cost is about half. Unfortunately the mainboard was the only board they were able to inspect and repair. They did inspect it and found it to be working normally which left me wondering about my tcon which they also indicated could be the problem. The tcon I had replaced came from ebay so I decided to purchase one from a company that sells parts rescued from TV's damaged in shipping. I installed the original mainboard and the "new" to me tcon in the tv, held my breath and plugged it in. Before, the center icon on the tv would light up and shortly it would start to flash 2/5 and you could not access the onboard menu and there were no backlights. Well, plugged it in and the icon didn't light up so.....I pressed the power button on the remote and........ the tv came on as though it had never been used asking what language I would prefer. You can't imagine my excitement!!! It was late so the next day I turned the tv on again and began searching the various functions and exploring the apps. After about 5 mins the tv went blank and the 2/5 came back.....but I was able to turn the tv off/on again (I did not unplug it) listen to an hour or so of Pandora which the tv connected to my wifi with no problems. The next day I contacted the company that sold me the tcon and described my problem and if they could ask their technicians what they thought about what was going on. The next day I received an email stating that the 2/5 code was a panel issue and since panels were so expensive I should search ebay for a new one. What??? If it was my panel why have I been able to watch several hours of Pandora and a 2 hour DVD since the replacement? It usualy happens not long after you turn the tv on but you can turn the tv off and back on and it seems to work fine. You'll remember that before the tv did not respond to the normal trouble shooting procedure of disconnecting the tcon cables or the corner cables, the screen always remained blank. Any thoughts? Should I live with it for now or should I search for another tcon? If the panel is bad why can I use the tv for several hours at a time with no problems? Anything else I should check?

thanks for your time.
Pete

[budwich]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

can't tell from your "wordage", did you try the "corner cable disconnect test" as suggested?

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

Yes, I had. Before I sent off my main board and purchased this last tcon board I had tried disconnecting each tcon cable individually and then each corner cable individually. At no time was there any response from the tv as far as any kind of picture and the backlights never even tried to come on, it was though the tv was "dead" except for the blinking center icon. I know the method is to disconnect one cable and then the next to see which part of the screen has a clear picture but I never had a picture at all so there was no way to tell if the tabs might need to be removed. When the tv is working the picture on the screen seems absolutely fine, no discoloration, no blurred motion, no lines horizontal or vertical, no strange pixels. It doesn't act at all like the typical "bad" tab bonds we've all read so much about on this forum.

Pete

[freakaftr8]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

It's possible you have a bunk tcon again. Did you replace all thermal pads when reinstalling

[ga70gto]

Re: Sharp 70" model LC-70LE733U 2-5 blinks

There was one thermal pad on each of what i'll call the central processing unit of both the main board and tcon. I made sure I installed both on the boards when I installed them.

Pete