AVS Forum banner

Status
Not open for further replies.
1 - 14 of 14 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter · #1 ·
Hello all,


I'm just about to buy a Panny TH-42PW4 and the dealer is going to let me check the plasma over before I buy it. What's the best way of spotting dead or defective pixels?


Is there anything else that I should be looking out for (except the buzzing)


Thanks


Reaps
 

·
Registered
Joined
·
925 Posts
if you want to really check for dead pixels carefully, make sure you feed it signal in such a way as to keep the internal scaler OFF. i fed mine native rate dot-by-dot with a computer and splashed solid color screens up of differing colors to look for dead pixels. i believe the service menu might have some solid color screens too (but don't quote me). if you have the internal scaler running it can make it a bit harder to notice things (depending on the source signal and how much scaling is being done).


doody.
 

·
Premium Member
Joined
·
8,098 Posts
The standard way of doing it is:

1. Totally white screen. Stand up close and try to spot a pixel that's not white (i.e., it could be black or a different color!).


2. Totally white screen. Usually this is ineffective, but try to see if there are no lit pixels.


3. Normal picture - try to see if you can spot a pixel that's not in sync with everything else.


It's a bit rare, these days, to see bad pixels. I'd be more careful to hear how loud the buzzing (if any buzzing is there).
 

·
Registered
Joined
·
32,172 Posts
I find the best way to check for dead pixels is a pixel-sniffing dog. Most lhasa apsos or shih tzus can be trained to sniff 'em out a mile away.


:)


Mark
 

·
Registered
Joined
·
1,570 Posts
Do a search on "Nokia monitor test software" I have posted before. That will help you isolate any malfunctioning pixels.
 

·
Registered
Joined
·
14 Posts
I just got a Panny 42" commercial model and found one dead pixel (on the whote screen saver it is blue.) I have not found others, but I have not really looked extremely hard. I can't tell it's there when watching from normal distance.


Is one or 2 dead pixels OK or should I return it as defective? Does it set a possible precedent for the unit that might cause trouble later?


Thanks for any info!


David
 

·
Banned
Joined
·
17,607 Posts
Dead pixels do not multiply. After the installation unless you have a major zap from thunderstorm or a surge. Most likely the pixel came like that. It is a small percentage. And not visible from 2 pic. heights right?




However if this pixels location coincides with the general area of the lower Bracket support screws, make sure that you did not overtightened the screws, sometimes overscrewing can drive a screw into the ribbon cables that drive entire left right pixels. That can be fixed but what a pain.
 

·
Registered
Joined
·
14 Posts
Cineramax,


Thanks for that information. It was very interesting.


I checked where the one dead pixel I found was and, looking at the screen, it is about 6-8 inches to the right and 1 inch above the lower left bracket screw. Should I try to loosen the screw a little?


I could not see it from 2 screen heights, but there is a lot of glare in the room so I may have to try later.


Thanks again,

David
 

·
Registered
Joined
·
72 Posts
Quote:
Originally posted by CINERAMAX
Dead pixels do not multiply. After the installation unless you have a major zap from thunderstorm or a surge. Most likely the pixel came like that. It is a small percentage. And not visible from 2 pic. heights right?


However if this pixels location coincides with the general area of the lower Bracket support screws, make sure that you did not overtightened the screws, sometimes overscrewing can drive a screw into the ribbon cables that drive entire left right pixels. That can be fixed but what a pain.
Hey Peter


What do you think about this? A previous customer found a stuck green sub pixel in his NEC 50MP2. It was not in the "A-Zone" so NEC said it was non-defective. I talked with a tech at NEC (Haley) and he said to have the customer run the "White Noise" for 24 hours, and that may help things out.


Well my customer did this, and now there is a new stuck blue sub-pixel on another spot. I called NEC back and they seem clueless as to why this happened. Any thoughts?
 

·
Registered
Joined
·
72 Posts
Hooray! My Samsung 170MP has no dead pixels.



Thanks Almighty1!


what a great program.
 
1 - 14 of 14 Posts
Status
Not open for further replies.
Top