My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the
lower part. A tech that came out said it was burn-in and would not be
covered under my warranty. I've seen burn-in on TVs and monitors before
and it has never had solid black dots like this, plus I have not ever
had any sort of static picture on the screen for any length of time that
could have caused burn-in.
This reminds me of a RAM chip on a computer display card with a bad
column address line. Does my HDTV have a digital frame buffer that could
have failed like this? Is there any sort of built-in diagnostic I could
access to test it?

--

Rick Jones
Remove the Extra Dot to e-mail me

Depends if ya used match or lighta for burn in.
"Rick Jones" wrote in message
...
My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the
lower part. A tech that came out said it was burn-in and would not be
covered under my warranty. I've seen burn-in on TVs and monitors before
and it has never had solid black dots like this, plus I have not ever
had any sort of static picture on the screen for any length of time that
could have caused burn-in.
This reminds me of a RAM chip on a computer display card with a bad
column address line. Does my HDTV have a digital frame buffer that could
have failed like this? Is there any sort of built-in diagnostic I could
access to test it?

--

Rick Jones
Remove the Extra Dot to e-mail me

Rick Jones wrote:
My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the
lower part. A tech that came out said it was burn-in and would not be
covered under my warranty. I've seen burn-in on TVs and monitors before
and it has never had solid black dots like this, plus I have not ever
had any sort of static picture on the screen for any length of time that
could have caused burn-in.
This reminds me of a RAM chip on a computer display card with a bad
column address line. Does my HDTV have a digital frame buffer that could
have failed like this? Is there any sort of built-in diagnostic I could
access to test it?

HDTV, if it is anything like European TV with double frame rate, will
have a RAM buffer.

---
Met vriendelijke groet,

Maarten Bakker.

"John Del" wrote in message
...
Subject: Mitsubishi WS55859 HDTV
From: Rick Jones
Date: 11/15/04 10:30 PM Eastern Standard Time
Message-id:

My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the
lower part. A tech that came out said it was burn-in and would not be
covered under my warranty.

Can't be burn in. Burns in CRT based projectors show up on the projected
image
as colored marks, not black. The burn is a subtracted color. A burn in
the
green tube will leave a magenta mark, a burn on the red tube leaves a cyan
mark, etc. In order for the marks to be black, the three tubes would need
to
physically occupy the same space (impossible).

If all three tubes are burned completely and the convergence is good, you
would get EXACTLY a black spot. This is likely not burn in, from the
description, however. If it is it is likely from a defect in the set to get
a pattern like that burned in. I have a customer with a similar model
describing a very similar symptom. It is out of town and I won't see it
until Thursday, but I will post what I find.

Leonard

"hoo-dair hoo-dat" hoo dair hoo writes:

Depends if ya used match or lighta for burn in.
"Rick Jones" wrote in message
...
My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the
lower part. A tech that came out said it was burn-in and would not be
covered under my warranty. I've seen burn-in on TVs and monitors before
and it has never had solid black dots like this, plus I have not ever
had any sort of static picture on the screen for any length of time that
could have caused burn-in.
This reminds me of a RAM chip on a computer display card with a bad
column address line. Does my HDTV have a digital frame buffer that could
have failed like this? Is there any sort of built-in diagnostic I could
access to test it?

That certainly doesn't sound like burn-in. What could you have been
displaying, a diagonal dot pattern for 3 months straight?

If the TV does progressive scan from NTSC, it has a frame buffer.
Switch between interlaced and progressive scan if that's an option - I
bet the locations of the dots moves.

If it can handle multiple formats, it probably has a frame butter.

Can you adjust things like position on the screen? If so, the dots
will move with the picture if it's a digital problem.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
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Important: Anything sent to the email address in the message header is ignored.
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Subject: Mitsubishi WS55859 HDTV
From: "Leonard Caillouet"
Date: 11/16/04 8:03 AM Eastern Standard Time
Message-id: eXmmd.7792$Dk.2102@lakeread08



If all three tubes are burned completely and the convergence is good, you
would get EXACTLY a black spot.

The marks that the OP are describing come from circuit failure, unless he was
watching that pattern (as Sam suggests is unlikely to say the least). While
those type of marks would burn on the same physical area of the CRTs, the
actual picture targets are not in the same location on the tubes. The green is
pretty much dead center while the red and blue images are off center in
opposite directions. For an experiment, disconnect the yokes on an old
scrapper projo (jump out any B+ feeds at sockets) and burn three marks in the
dead center of each tube. You'll find three colored marks on the screen.

The only time I've ever seen black marks is when the burns are large and
overlap at some point.

Can you post an image of this for us to see?

--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd


"Rick Jones" wrote in message
...
My Mitsubishi has a series of black dots spaced at regular intervals
running diagonally across the screen and then repeating again on the lower
part. A tech that came out said it was burn-in and would not be covered
under my warranty. I've seen burn-in on TVs and monitors before and it has
never had solid black dots like this, plus I have not ever had any sort of
static picture on the screen for any length of time that could have caused
burn-in.
This reminds me of a RAM chip on a computer display card with a bad
column address line. Does my HDTV have a digital frame buffer that could
have failed like this? Is there any sort of built-in diagnostic I could
access to test it?

--

Rick Jones
Remove the Extra Dot to e-mail me

Shoreline Electronics wrote:

Can you post an image of this for us to see?

Are binaries allowed here or do I need to put it on a web page?

--

Rick Jones
Remove the Extra Dot to e-mail me

How come we choose from just two people for President and fifty
for Miss America?

Web page

Can you imagine John Kerry or George W in a bikini?? Yukkers A Strong
Third party may even be welcome!!
"Rick Jones" wrote in message
...
Shoreline Electronics wrote:

Can you post an image of this for us to see?

Are binaries allowed here or do I need to put it on a web page?

--

Rick Jones
Remove the Extra Dot to e-mail me

How come we choose from just two people for President and fifty
for Miss America?

Shoreline Electronics wrote:
Can you post an image of this for us to see?

I've placed a photo of the screen showing the dots at:
http://www.geocities.com/seventysixi.../PB230070a.JPG
Ignore the orange spot in the upper left corner, it's just a
reflection from the overhead light. I do not see how the technician
could call this burnin. I have never seen burnin on a TV or monitor like
this. The regular, repeating pattern looks like a failure of some memory
segments, if I understand correctly how the electronics of this TV
works. Unfortunately, since it's been diagnosed as burnin by the tech
that came to look at it my extended service provider is claiming repair
isn't covered under my warranty.

--

Rick Jones
Remove the Extra Dot to e-mail me

"The great object is that every man be armed... Everyone who is
able may have a gun." -Patrick Henry

Subject: Mitsubishi WS55859 HDTV
From: Rick Jones
Date: 11/24/04 9:56 AM Eastern Standard Time
Message-id:

I've placed a photo of the screen showing the dots at:
http://www.geocities.com/seventysixi.../PB230070a.JPG
Ignore the orange spot in the upper left corner, it's just a
reflection from the overhead light. I do not see how the technician
could call this burnin.

I don't know of any pattern you could have been watching that would cause a
burn pattern like this.

Did the technicial look directly into the tubes when turned off? Shining a
bright light (sharply focused LED lights are great for this) directly into the
lens assy of each tube would quickly confirm any burns on the faceplate of the
CRTs. If he didn't, he didn't do his job.

Besides, just because a tube is burned (and I don't believe yours are), doesn't
place the blame on the consumer necessarily. Burns also happen when there are
failures of the chassis (or an individual tube). Such burns are still covered
by warranty. Of course, pattern burns from games, test patterns, station
logos, phone numbers, stock tickers, etc. are not warranty compensable.

Get a hold of Mitsu and scream until something gets done. Even if you need to
pay a non-authorized independant tech to disassemble and confirm the tube
conditions, it would be well worth it.

John

John Del wrote:

Subject: Mitsubishi WS55859 HDTV
From: Rick Jones
I've placed a photo of the screen showing the dots at:
http://www.geocities.com/seventysixi.../PB230070a.JPG
Ignore the orange spot in the upper left corner, it's just a
reflection from the overhead light. I do not see how the technician
could call this burnin.


I don't know of any pattern you could have been watching that would cause a
burn pattern like this.


Get a hold of Mitsu and scream until something gets done. Even if you need to
pay a non-authorized independant tech to disassemble and confirm the tube
conditions, it would be well worth it.

Well, I may actually get something resolved on this, after having to
live with this ugly problem for the past year. I had a tech come out
last week while I was on vacation for the annual cleaning I'm allowed
under my extended warranty.
This time the Phillips people (whom the extended warranty is
through) used a different service provider. This tech took a more
thorough look at things than the guy a year ago and pretty much proved
it isn't burnin. Going into the convergence controls and moving the 3
color positions widely apart showed that the spots move with the signal,
whereas if it was really burnin on the tubes they would have stayed put.
I also noted, for the very first time, that when the TV's menu is
displayed (not the satellite guide) the dots don't appear on the menu
but can still be seen on the rest of the picture. The menu display
overlays the dots. So the problem seems to be somewhere in the signal
processing.
He's gotta check with Mitsubishi on the possible causes, and get
Phillips to reauthorize repair after the previous techs screwup, but
hopefully it's going to get fixed soon.

--

Rick Jones
Remove the Extra Dot to e-mail me

Generally speaking, you aren't learning much when your lips are
moving.