Sharp LC-46D62U Static Dots and Lines on Screen

[kca]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

Thinking about picking up this set for free tonight (please see images).

It's the Sharp LC-46D82U model.


Freakaftr8 (and others) ~ Is this what yours looked like?

If so, I can tell from reading this post over that it will be the IC on the mainboard as the culprit.

[Savario]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

I have LC-32D62U model and same issues. IC3502 seems to be the problem on my set. Here is info on these chips from Service Manual

IC3501/3502 (RH-iXB822WJQZQ)
These ICs are 128-Mbit GDDR SDRAM (Graphic Double Data Rate Synchronous DRAM), providing a memory for image processing and buffering
OSD data.

On my TV the dots are not static. They are moving as displaying as white horizontal lines. Applying some pressure to one of the SDRAM chips at a specific point can cause the lines to stop moving and appear frozen. At this point turning the TV off, waiting for the click and turning it back on can clear the screen memory. TV might work for a while until the problem re-appears.

[Neuf]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

I just wanted to post and say I had the same issue. My sharp is about 12 years old now. I used my wife's hair dryer. It worked at first for a minute, but green lines came back. I then took off the black rubber covers and heated again. It worked for a minute but green lines canes back. Finally, I put the black covers with the white stuff back on and reheated. This time the green lines stayed away. I put it all back together. I just watched a 2 hour movie without issue. I will post back later if the lines return. Thanks for the help! You guys rock!

[Neuf]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

I just wanted to post and say I had the same issue. My sharp is about 12 years old now. I used my wife's hair dryer. It worked at first for a minute, but green lines came back. I then took off the black rubber covers and heated again. It worked for a minute but green lines canes back. Finally, I put the black covers with the white stuff back on and reheated. This time the green lines stayed away. I put it all back together. I just watched a 2 hour movie without issue. I will post back later if the lines return. Thanks for the help! You guys rock!

The lines came back a few days later and I put the TV back in the closet. I am going to try and reflow again tonight. I will post an update soon.

[Neuf]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

The lines came back a few days later and I put the TV back in the closet. I am going to try and reflow again tonight. I will post an update soon.

Worked last night but green lines/dot all back this morning. Top of screen is still normal but most of the rest is covered with green dots/line again. Anything else I can do? Can I try getting more of the white substance under the rubber covers and reheat? What is that substance called?

[guizmophil]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

I'm glad I found this thread. I'd like to thank all of you who shared this information publicly.

I was able to fix my 14 years old LC-32D62U following the instructions in this thread!

I must have re-assembled the damn thing 6 times, because it was good, power cycled multiple time, then when I was assembling everything back, the problem was back.

In the end I suspected that the chip was losing connection with the board when it was getting cold. Power cycling a lot of times in a row doesn't really let the chip cool down, so solder doesn't have time to contract completly.

I ended up adding a bunch of stacked thermal pads I had laying from the days of my Phat PS3, so that they could reach that little "heatsink bracket" used to cool down the ATi, the Toshiba and another chip I forgot the name.

Also replaced the 3 thermal pads from those chip while I was there, the other were dry as hell.

I've attached a picture of my ghetto thermal pad tower.

[guizmophil]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

Oh yeah and the plastic pins were so dry that they exploded when I tried to remove them from the heatsink-bracket to the board.

As you can see on the same picture, I now have a nylon bolt+nut instead to old the bracket.

Had these from back in the days when I had a Mac Mini from 2007, had to replace the one from the heatsink in there back then and had just two extra remaining I used just now for the TV!

If there's a lesson to be learned from this today, don't throw away thermal pads or other small electronic component when you no longer need them, because you might need them some day!

[xadas]

Re: Sharp LC-46D62U Static Dots and Lines on Screen

Yes, the internet can be a cesspool at times, but every now and again, it comes through with some valuable information!

I've got a Sharp LC-32D62U and the same issue as the OP (mostly static green dots overlaying screen). Internal LCD test patterns were fine. Found the problem IC 3502 (not IC 502 as originally stated). Applying pressure to IC 3502 caused some dots to disappear, although the issue remained. Doing the same to IC 3501 (nearby identical chip) had no effect.

From the LC-32D62U manual:

"10. IC3501/3502 (RH-iXB822WJQZQ)
These ICs are 128-Mbit GDDR SDRAM (Graphic Double Data Rate Synchronous DRAM), providing a memory for image processing and buffering OSD data."

I applied some kapton tape around IC 3502, and gently warmed it up with the heat gun set at 160C. I did this for about 2-3 minutes. I then applied some no-clean flux paste (8341) to each side of the IC, and then cranked it up to 200C. I heated the IC for about 2-3 minutes. In effect, I followed what this youtuber recommended:

"I fixed a broken 47” TV with HEAT | HDMI ports not working on LG 47LE5400"
https://www.youtube.com/watch?v=CLLADvGJiSU

I then reattached the main board and turned on the TV. The top 1/8 of the screen was now free of the green dots, but the rest of the screen was still covered as before. I then power cycled the TV (pressed the off button, and then the on button), and then.....

No more green dots!! This c. 2007 LCD TV is now back in business!

Thanks to freakaftr8 and jotvguy and all the other posters!

PS - if anyone finds a way to completely bypass the main board and use a "LCD controller" let us all know. Something along the lines of what this guy managed to do:

Re-using a Broken Television as a Monitor. Part 1
https://www.youtube.com/watch?v=9EuD2UNrelg&t=226s

PPS - I'll repost if the fix doesn't hold, but so far, so good.