I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...a-is.com/r.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/b.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/g.jpg
https://ssl.perfora.net/secure.na-is...-is.com/bl.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/c.jpg
https://ssl.perfora.net/secure.na-is...-is.com/r2.jpg
https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg

On Dec 13, 3:45 pm, Meat Plow wrote:
On Thu, 13 Dec 2007 09:40:43 -0800, N|A-Orion wrote:
I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...a-is.com/r.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/b.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/g.jpg
https://ssl.perfora.net/secure.na-is...-is.com/bl.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/c.jpg
https://ssl.perfora.net/secure.na-is...-is.com/r2.jpg
https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg

Have you looked down into the projector tube through the lens with a
flashlight and noticed anything odd looking? Stuff like that usually shows
up pretty easily and you can have a good look down in the tube through the
lens if the fluid isn't too cloudy. I've looked in mine after cleaning and
a repair and noticed fibers or even hairs in the fluid right from the
factory. These are magnified by the lens but otherwise too small to appear
on the screen.- Hide quoted text -

- Show quoted text -

I'd have to pull the screen to look at it from that angle, and I'm
selling the tv so I don't really want to go through the hassle. I'm
selling to a co-worker, so I'm really mainly looking for a "what to
expect" From what I can tell they are just going to have to deal with
the discoloration which they don't mind for the price they got. I'm
just making sure something more serious is not going to come from this
and have her breaking my door down

N|A-Orion wrote:

On Dec 13, 3:45 pm, Meat Plow wrote:

On Thu, 13 Dec 2007 09:40:43 -0800, N|A-Orion wrote:

I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...a-is.com/r.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/b.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/g.jpg
https://ssl.perfora.net/secure.na-is...-is.com/bl.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/c.jpg
https://ssl.perfora.net/secure.na-is...-is.com/r2.jpg
https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg

Have you looked down into the projector tube through the lens with a
flashlight and noticed anything odd looking? Stuff like that usually shows
up pretty easily and you can have a good look down in the tube through the
lens if the fluid isn't too cloudy. I've looked in mine after cleaning and
a repair and noticed fibers or even hairs in the fluid right from the
factory. These are magnified by the lens but otherwise too small to appear
on the screen.- Hide quoted text -

- Show quoted text -


I'd have to pull the screen to look at it from that angle, and I'm
selling the tv so I don't really want to go through the hassle. I'm
selling to a co-worker, so I'm really mainly looking for a "what to
expect" From what I can tell they are just going to have to deal with
the discoloration which they don't mind for the price they got. I'm
just making sure something more serious is not going to come from this
and have her breaking my door down

Well, the tube is certainly not cracked - it wouldn't work if it were.

You burned the line into the phosphor of the red crt by turning up the
red drive too high.
I remember seeing a Hitachi service bulletin out to put with the
adjustment manual warning not to do exactly what you just did.

The set would go into protect shutdown when the drive was too high.
The shutdown would collapse the horizontal drive, but the drive was so
high on the red that it was at so high a level it was still driving
the tube when ti collapsed.

The mark will never go away.

One of the other tech's where I worked did exactly what you did by
accident. The tube had to be replaced.


On Dec 13, 12:40 pm, "N|A-Orion" wrote:
I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg

"N|A-Orion" wrote in message
...
I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...a-is.com/r.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/b.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/g.jpg
https://ssl.perfora.net/secure.na-is...-is.com/bl.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/c.jpg
https://ssl.perfora.net/secure.na-is...-is.com/r2.jpg
https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg


It looks like you burned the phosphor, the tube isn't cracked but it may as
well be. It looks like there was a momentary loss of deflection, perhaps a
poorly designed protection circuit didn't kill the beam before shutting down
the horizontal deflection.

On Dec 14, 9:59 am, Meat Plow wrote:
On Fri, 14 Dec 2007 03:26:14 +0000, James Sweet wrote:

"N|A-Orion" wrote in message
...
I have a 52" Hitachi rear projection HDTV. The red gun was too hot and
throwing off the colors of the display, so I opened up the bottom of
the cabinet to see if there was anything that could be adjusted/
cleaned up to try and correct the color. I found a series of knobs
that adjust the intensity and focus of each crt, and began to test the
sensitivity of the knob and how much they needed to be turned to
acheive a certain amount of adjustment. Apparently I turned the red
gun up way too high and the display turned off. I turned the red back
down, turned the tv back on, and now have what appears to be a "crack"
at the top of the red gun. I am not sure if this is in a lens, or a
coating, or the crt itself. I was wondering if anyone could take a
look at these pictures and advise me what the issue is.

https://ssl.perfora.net/secure.na-is...a-is.com/r.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/b.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/g.jpg
https://ssl.perfora.net/secure.na-is...-is.com/bl.jpg
https://ssl.perfora.net/secure.na-is...a-is.com/c.jpg
https://ssl.perfora.net/secure.na-is...-is.com/r2.jpg
https://ssl.perfora.net/secure.na-is...-is.com/c2.jpg

It looks like you burned the phosphor, the tube isn't cracked but it may as
well be. It looks like there was a momentary loss of deflection, perhaps a
poorly designed protection circuit didn't kill the beam before shutting down
the horizontal deflection.

Samsung had this protection problem IIRC.- Hide quoted text -

- Show quoted text -

So if it's burned phospor, is it as harmless as screen burn in? The
person who now has the TV does not mind the line, I just want to make
sure that nothing else is going to break down the line b/c of this
issue.

So if it's burned phospor, is it as harmless as screen burn in? The
person who now has the TV does not mind the line, I just want to make
sure that nothing else is going to break down the line b/c of this
issue.


Screen burn and burned phosphor are one and the same, yes, it's harmless,
just ugly.