Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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James Sweet
 
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Default Viewsonic P225F horizontal failure

Got a P225F flat CRT monitor brought over this weekend with the horizontal
compressed into a band about 1/4" wide from top to bottom. HOT checks out
ok, found a 0.8A plastic cased micro fuse that's blown, everything else I've
checked so far looks ok. Anybody deal with this one before? I'm tempted to
replace the fuse and see what happens, but I expect it to blow again.


  #2   Report Post  
Phil Durgin
 
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Default Viewsonic P225F horizontal failure

You probably have a bad HOT and P-FET 2sj306 that is shorted as well.

Phil


"James Sweet" wrote in message
...
Got a P225F flat CRT monitor brought over this weekend with the horizontal
compressed into a band about 1/4" wide from top to bottom. HOT checks out
ok, found a 0.8A plastic cased micro fuse that's blown, everything else
I've
checked so far looks ok. Anybody deal with this one before? I'm tempted to
replace the fuse and see what happens, but I expect it to blow again.




  #3   Report Post  
ChrisCoaster
 
Posts: n/a
Default Viewsonic P225F horizontal failure

"Phil Durgin" wrote in message hlink.net...
You probably have a bad HOT and P-FET 2sj306 that is shorted as well.

Phil


"James Sweet" wrote in message
...
Got a P225F flat CRT monitor brought over this weekend with the horizontal
compressed into a band about 1/4" wide from top to bottom. HOT checks out
ok, found a 0.8A plastic cased micro fuse that's blown, everything else
I've
checked so far looks ok. Anybody deal with this one before? I'm tempted to
replace the fuse and see what happens, but I expect it to blow again.

________________
This a general suggestion for anyone owning or desiring to own an LCD
flat monitor, including James:

The following suggestions may seem valid only for traditional CRT
monitors & TVs, but heat is heat, and brighter generates more of the
same.

1. Where are your brightness/contrast settings? If they look
something like this:
Min.IIIIIIIIIIIIIIIIII Max,

TURN THEM DOWN!! I usually keep my Brightness at the middle, and my
contrast a little higher.

2. Explore your color driver section. Some mfgs crank their R, G, B
drives to the max. If this is your case, pull them all back to about
the middle. If one is more than the other, pull them all back in the
same ratio. IE:

R Min.IIIIIIIIIIIIIIIII Max.
G Min.IIIIIIIIIIIIII Max.
B Min.IIIIIIIIIIIIII Max.

Pull them back as follows:
R Min.IIIIIIIIII Max.
G Min.IIIIIIIII Max.
B Min.IIIIIIIII Max.

(All of the above depends on your specific menus of course!)

3. If you have a "Color Temperature" menu option, set it to 6500K
instead of 8000 or whatever the higher(hotter) setting is. Although
if you adjust #1 and #2 individually, Color Temp may display "USER"
which is fine.

All of this will have the effect of a deeper, richer image. It WILL
seem darker to you at first, but remember, "Brighter ain't always
better".

What you will be seeing is more representative of real life. IE if
your wallpaper is a baseball stadium at night, it should LOOK like a
stadium at night, not like a stadium at twilight. The sky over
NYC should be a rich light blue, not whiteish turquoise, and any
shadows on the buildings's setbacks should be a dark gray, not ashen.
If you are watching a DVD, the image should convey *most* of the
director's intentions.

Finally, it will also add significantly to the life of your monitor,
whether CRT, Plasma, or LCD.

regards,

CC
  #4   Report Post  
Jerry Greenberg
 
Posts: n/a
Default Viewsonic P225F horizontal failure

LCD monitors do not wear faster with higher contrast settings. The LCD
display is a passive device using a light source behind it. There is a
backplane with a back light. The front has a polarizer filter. The
crystal segments each representing a pixel or light point twist to
change the polar or polarity of the light.

The brightness control in some models does not change the brightness
of the lamp. It changes the average polar resting position of the base
reference for the crystal segments. You cannot burn in an LCD monitor.

The backplane lamps are usually rated to about 20,000 to 30,000 hours.
This means that the lamp emission will be at 50% of its nominal rating
after its rating is reached.

As for Plasma displays these are much like a CRT. If the contrast is
set high, the lifespan will be reduced. Setting the brightness too
high, also reduces its lifespan, just like a picture tube.

In any case the black level should be set where the background just
reaches black where it should be black. The contrast should be set to
have a desirable viewing level for the highlights.

With any of these monitors, running it at a higher colour temperature
will not reduce the display life. It is the total lumance of the
screen that will reduce the Plasma or CRT life span, not the colour
temperature it is working at.

Plasma monitors should last about 30,000 hours average, to reach their
50% nominal performance for luminance.

At about 12 to 15 hours use per day, you should get very good
performance out of a CRT, LCD back plain lamps, or a Plasma for about
4 to 5 years. If you want to rate it to its 50% nominal, then you can
push it to about 6 to 8 years on the average.

When considering a Plasma display, this should only be purchased where
it is absolutly required. They are very suseptable for burnin, and
also are very expensive for their life span.

Jerry G.
========


(ChrisCoaster) wrote in message . com...
"Phil Durgin" wrote in message hlink.net...
You probably have a bad HOT and P-FET 2sj306 that is shorted as well.

Phil


"James Sweet" wrote in message
...
Got a P225F flat CRT monitor brought over this weekend with the horizontal
compressed into a band about 1/4" wide from top to bottom. HOT checks out
ok, found a 0.8A plastic cased micro fuse that's blown, everything else
I've
checked so far looks ok. Anybody deal with this one before? I'm tempted to
replace the fuse and see what happens, but I expect it to blow again.

________________
This a general suggestion for anyone owning or desiring to own an LCD
flat monitor, including James:

The following suggestions may seem valid only for traditional CRT
monitors & TVs, but heat is heat, and brighter generates more of the
same.

1. Where are your brightness/contrast settings? If they look
something like this:
Min.IIIIIIIIIIIIIIIIII Max,

TURN THEM DOWN!! I usually keep my Brightness at the middle, and my
contrast a little higher.

2. Explore your color driver section. Some mfgs crank their R, G, B
drives to the max. If this is your case, pull them all back to about
the middle. If one is more than the other, pull them all back in the
same ratio. IE:

R Min.IIIIIIIIIIIIIIIII Max.
G Min.IIIIIIIIIIIIII Max.
B Min.IIIIIIIIIIIIII Max.

Pull them back as follows:
R Min.IIIIIIIIII Max.
G Min.IIIIIIIII Max.
B Min.IIIIIIIII Max.

(All of the above depends on your specific menus of course!)

3. If you have a "Color Temperature" menu option, set it to 6500K
instead of 8000 or whatever the higher(hotter) setting is. Although
if you adjust #1 and #2 individually, Color Temp may display "USER"
which is fine.

All of this will have the effect of a deeper, richer image. It WILL
seem darker to you at first, but remember, "Brighter ain't always
better".

What you will be seeing is more representative of real life. IE if
your wallpaper is a baseball stadium at night, it should LOOK like a
stadium at night, not like a stadium at twilight. The sky over
NYC should be a rich light blue, not whiteish turquoise, and any
shadows on the buildings's setbacks should be a dark gray, not ashen.
If you are watching a DVD, the image should convey *most* of the
director's intentions.

Finally, it will also add significantly to the life of your monitor,
whether CRT, Plasma, or LCD.

regards,

CC

  #5   Report Post  
James Sweet
 
Posts: n/a
Default Viewsonic P225F horizontal failure


"ChrisCoaster" wrote in message
om...
"Phil Durgin" wrote in message

hlink.net...
You probably have a bad HOT and P-FET 2sj306 that is shorted as well.

Phil


"James Sweet" wrote in message
...
Got a P225F flat CRT monitor brought over this weekend with the

horizontal
compressed into a band about 1/4" wide from top to bottom. HOT checks

out
ok, found a 0.8A plastic cased micro fuse that's blown, everything

else
I've
checked so far looks ok. Anybody deal with this one before? I'm

tempted to
replace the fuse and see what happens, but I expect it to blow again.

________________
This a general suggestion for anyone owning or desiring to own an LCD
flat monitor, including James:

The following suggestions may seem valid only for traditional CRT
monitors & TVs, but heat is heat, and brighter generates more of the
same.

1. Where are your brightness/contrast settings? If they look
something like this:
Min.IIIIIIIIIIIIIIIIII Max,

TURN THEM DOWN!! I usually keep my Brightness at the middle, and my
contrast a little higher.

2. Explore your color driver section. Some mfgs crank their R, G, B
drives to the max. If this is your case, pull them all back to about
the middle. If one is more than the other, pull them all back in the
same ratio. IE:

R Min.IIIIIIIIIIIIIIIII Max.
G Min.IIIIIIIIIIIIII Max.
B Min.IIIIIIIIIIIIII Max.

Pull them back as follows:
R Min.IIIIIIIIII Max.
G Min.IIIIIIIII Max.
B Min.IIIIIIIII Max.

(All of the above depends on your specific menus of course!)

3. If you have a "Color Temperature" menu option, set it to 6500K
instead of 8000 or whatever the higher(hotter) setting is. Although
if you adjust #1 and #2 individually, Color Temp may display "USER"
which is fine.

All of this will have the effect of a deeper, richer image. It WILL
seem darker to you at first, but remember, "Brighter ain't always
better".

What you will be seeing is more representative of real life. IE if
your wallpaper is a baseball stadium at night, it should LOOK like a
stadium at night, not like a stadium at twilight. The sky over
NYC should be a rich light blue, not whiteish turquoise, and any
shadows on the buildings's setbacks should be a dark gray, not ashen.
If you are watching a DVD, the image should convey *most* of the
director's intentions.

Finally, it will also add significantly to the life of your monitor,
whether CRT, Plasma, or LCD.

regards,

CC



All good advice, but what's this have to do with my post? This is a CRT
monitor that I'm repairing for someone else, I can advise them how to
configure it but in the end that's their business, all I need to do is make
it work.


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