Sharp LC-46D62U Static Dots and Lines on Screen

[Shinju]

So since I have never had a Sharp before and nothing else to fix at the moment I took pitty on this ole gal and decided to tinker with it and see.

I have not cracked the shell yet and I plan on it tonight so I will post nudes later this evening.

I am guessing this is probably a t-con or mainboard issue. I plan on cleaning and reseating all flat cables and going from there after.

Does Sharp have a service menu to access test patterns?

I ran the panel for 6 hours and no change, if it was a panel fault in my experience with those it would have gotten worse or the image would have suffered more. The image behind the lines/dots looks normal if you will.

Thanks

-Shin

[tom66]

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

To access the service menu.

Disconnect mains power.
Hold INPUT and VOL- on the set's buttons, then plug power in.
Wait for power to come on, you may have to hold up to 30 seconds.
When TV turns on, "K" appears in corner. If it does not, repeat step 2.
If "K" has appeared press VOL- and CH- to access service menu.

When in the service menu, test patterns are accessed in one of many possible locations. Usually under "LCD TEST." I can't tell you where because it's different on every Sharp I have seen. Navigation is through VOL-/+ and CH-/CH+ on remote.

[Shinju]

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

To access the service menu.

Disconnect mains power.
Hold INPUT and VOL- on the set's buttons, then plug power in.
Wait for power to come on, you may have to hold up to 30 seconds.
When TV turns on, "K" appears in corner. If it does not, repeat step 2.
If "K" has appeared press VOL- and CH- to access service menu.

When in the service menu, test patterns are accessed in one of many possible locations. Usually under "LCD TEST." I can't tell you where because it's different on every Sharp I have seen. Navigation is through VOL-/+ and CH-/CH+ on remote.

Awesome information Tom66! I will give those a go before I bust it open!

Holy moly the Mainboard for this unit is NOT CHEAP!

[freakaftr8]

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

Thus is the mainboard. An ic on the very top is the culprit. Post a pic of the board I'll show you which one. I've been through this before. It's a BGA style ic. It needs heat reflow.

[Shinju]

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

Thus is the mainboard. An ic on the very top is the culprit. Post a pic of the board I'll show you which one. I've been through this before. It's a BGA style ic. It needs heat reflow.

Nice! Thanks for the tip!

Do you know if the reflow is a perm fix or does it come back? I see several revisions of the mainboard for this panel some with a giant heatsink covering 35% of the board others without it.

And I will post a photo of my mainboard this evening

[freakaftr8]

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

As far as I know. I had to reflow three times in the beginning. It's been 6 months and still going strong.

You can apply a litt heat at first and watch the screen to see if it clears up. You may have to power cycle the tv as your doing this. It had a tendency to hold the image as this ic has something to do with the ram on the board.

[Shinju]

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

Test patterns come up good as gold.

[Shinju]

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

Mainboard shot.

[freakaftr8]

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

okay so that that picture was taken on the side. but if you look at the 4 pin connector looking straight down from the top of the TV the chip is a square chip located right next to that 4 pin right at the top push on it and watch the screen change the dots may even disappear. you can actually get to this chip with your pinky finger between the metal heat sink so you probably won't need to remove the heat sink right away let us know what you find out

[Shinju]

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

I assume you are talking about the top most ram DAC chip?

Pressing on either one of those or the bigger chip does nothing. I tried a toaster oven reflow running the temp up to 450degrees 210c, turning the oven off and letting it cool to below 50C.


No real change maybe I will try to reflow again.

[freakaftr8]

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

The ramdac chip with etron tech imprinted on it. The furthest from the lvds cable. Try some directed heat on it. It's labeled IC 502

[Shinju]

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

I dont have a heat gun, I can try a hair dryer lol. I need to replace my burnt out gun, maybe I will pick one up this weekend.

[freakaftr8]

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

Hair dryer might do to see if it changes. with that chip when I heated it I've seen everything from an array of dots and crap all over the screen to just a couple lines and dots to just a few. Depending on how much heat and how hard I pressed on that ship like I said it took me two or three good tries with heat to finally see the chip and reflow of the BGA connections. I have done this with two sharps now both the same model number as yours

[Shinju]

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

I'll give it a go, safe to run the panel while the heat sink is off the other chips?

[freakaftr8]

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

for a little while yes I never let it get way too hot but I ran it for probably 10 minutes with no problems

remember it's a RAMDAC chip so power cycle the TV a few times while you're heating it up to see if it changes

[Shinju]

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

Got it! Gonna eat some food and get back to it.

[Shinju]

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

No change, I am not sure what is going on sometimes the dots are almost gone, lines are still present turn the unit off wait for the ps to click and turn it back and and BAM all the dots are back in full force.

[freakaftr8]

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

Odd. Normally I didn't wait for the power supply to fully shut down just a quick off and on.
Mine acted the same way. Sometimes a perfect picture.

[Shinju]

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

Tried that too, maybe the board is shot. I have applied pressure to every ball soldier chip and then some and nothing changes.

[freakaftr8]

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

That chip was super stubborn. I finally got it though. You tried flexing the board?