Computer monitor has no Red component - is this fixable?

D

D. M.

Guest
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
<danmont@umiich.edu.nospam>
 
"D. M." <danmont@umich.edu.nospam> wrote in message
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com...
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
Click to expand...
When you buy a "pig in a poke", sometimes you get a pig. Sounds like the red
gun, or driver circuit is shot.
 
D. M. <danmont@umich.edu.nospam> wrote in
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com:
Hi Dan,
Unfortunately in most cases this problem is caused by bad CRT, which puts
it in the "not worth fixing" category. It could perhaps be revived with a
CRT rejuvenator, but such fix is not guaranteed (it could also kill the CRT
entirely) and is only temporary.
There is a slim chance that the red channel amplifier is malfunctioning,
which can be tested by comparing voltages against a working channel, but it
is a dangerous task if you are not familiar with the procedure.
Last, it might be possible to boost the red channel (if the red color is
just weaker, but still showing on the screen) using internal gain controls,
but this is not a proper fix either and will give a mediocre picture at
best.

Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam
Click to expand...
 
Fellow Human <none@nospam.com> writes:

D. M. <danmont@umich.edu.nospam> wrote in
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com:
Hi Dan,
Unfortunately in most cases this problem is caused by bad CRT, which puts
it in the "not worth fixing" category. It could perhaps be revived with a
CRT rejuvenator, but such fix is not guaranteed (it could also kill the CRT
entirely) and is only temporary.
Click to expand...
Baldersdash. :) Most common problem causing lack of a color are bad solder
connections on the CRT neck board. Or, even a bent over pin in the VGA
cable. Next would be a bad driver. Last would be a bad CRT.

See the Monitor Repair Guide at the site below.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.


There is a slim chance that the red channel amplifier is malfunctioning,
which can be tested by comparing voltages against a working channel, but it
is a dangerous task if you are not familiar with the procedure.
Last, it might be possible to boost the red channel (if the red color is
just weaker, but still showing on the screen) using internal gain controls,
but this is not a proper fix either and will give a mediocre picture at
best.

Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam
Click to expand...
 
Generally people only sell their monitors when there is a problem with them.
Good monitors are rarely sold...

The fault may be with the red colour channel. The supply to the red video
drivers, and the bias voltages to the CRT red gun should be verified to
determine the area of fault to begin with.

If you paid a lot for this monitor, it may pay for you to get an estimate on
it before taking the decision to chuck it out.

You would be better off buying a low cost new monitor with a good warranty
than buying a used one with no warranty. The newer models are very well
made, and perform well for the price.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
=========================================


"D. M." <danmont@umich.edu.nospam> wrote in message
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com...
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
<danmont@umiich.edu.nospam>
 
"D. M." <danmont@umich.edu.nospam> wrote in message
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com...
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).
Click to expand...
Try jumpering the green output to the red one AT THE TUBE CATHODES. you
should get yellow for
any green input-this proves tube good. Or, ground red tube pin, turn on
monitor,
should get red screen (do not run long like this!!!!)
Bad solder on tube sockets also common...

Viper

Dan M.
danmont@umiich.edu.nospam
Click to expand...
 
FIRST do something simpe like check to see if you have any bad pins in
the connector.

I had a Dell monitor with a captive cable that had three broken pins -
fortunately 2 were ground.

I bent a small solid wire (like an "L") and stuck it into the socket.
It was just enought to contact the broken pin. Make sure the foot of
the "L" isn't long enough to short other pins or the shell.
 
D. M. wrote:
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam
Click to expand...

Every time I've seen a missing color on a 21" Viewsonic it has been
caused by a bad video driver IC. It ususally fails because they didn't
use any silicone heat sink compound between the IC and the heat sink.
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but the
cost is more than a 21" monitor is worth in my area. What's the number
of the IC on the big heat sink on the circuit board that's plugged
directly into the CRT? Also, what's the model number? One of the ICs
that caused all the problems was an EY07P, but there were other types
that also tended to fail.
--
Andy Cuffe
baltimora@psu.edu
 
On Thu, 25 Sep 2003 14:44:41 GMT, Andy Cuffe <baltimora@psu.edu>
wrote:

D. M. wrote:

Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam


Every time I've seen a missing color on a 21" Viewsonic it has been
caused by a bad video driver IC. It ususally fails because they didn't
use any silicone heat sink compound between the IC and the heat sink.
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but the
cost is more than a 21" monitor is worth in my area. What's the number
of the IC on the big heat sink on the circuit board that's plugged
directly into the CRT? Also, what's the model number? One of the ICs
that caused all the problems was an EY07P, but there were other types
that also tended to fail.
Click to expand...
I'm at work and the monitor is at home. I'll get the info and post it
here. I do know that it is a Viewsonic 21PS. I only paid $50 for the
monitor, so I won't be out a great amount. I bought it from the
surplus property disposition center at the university here. I was
going to buy a smaller monitor for $25 but saw this one all by itself
way up on the top shelf and thought what the hell and went for it.

Dan M.
 
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but
the
cost is more than a 21" monitor is worth in my area.
Click to expand...
$50-$100 for a 21" Viewsonic? Really? That cheap? If I could find one
that cheap around here, my world would not be blue (see my post further
down). New, they want $400+ and the cheapest 21" I have seen here was
like $250, but that was a while ago.

I suppose I could go ebay, but then I have to pay UPS and worry about
them using it for field goal practice or whatever it is they do to bust
monitors.


"Andy Cuffe" <baltimora@psu.edu> wrote in message
news:3F730071.525E@psu.edu...
D. M. wrote:

Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I
adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise
I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam


Every time I've seen a missing color on a 21" Viewsonic it has been
caused by a bad video driver IC. It ususally fails because they
didn't
use any silicone heat sink compound between the IC and the heat sink.
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but
the
cost is more than a 21" monitor is worth in my area. What's the
number
of the IC on the big heat sink on the circuit board that's plugged
directly into the CRT? Also, what's the model number? One of the ICs
that caused all the problems was an EY07P, but there were other types
that also tended to fail.
--
Andy Cuffe
baltimora@psu.edu
Click to expand...
 
UPS could break an anvil!

"Eric Vey" <junk@ericvey.com> wrote in message
news:bkvaev$6kauu$1@ID-61706.news.uni-berlin.de...
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but
the
cost is more than a 21" monitor is worth in my area.

$50-$100 for a 21" Viewsonic? Really? That cheap? If I could find one
that cheap around here, my world would not be blue (see my post further
down). New, they want $400+ and the cheapest 21" I have seen here was
like $250, but that was a while ago.

I suppose I could go ebay, but then I have to pay UPS and worry about
them using it for field goal practice or whatever it is they do to bust
monitors.


"Andy Cuffe" <baltimora@psu.edu> wrote in message
news:3F730071.525E@psu.edu...
D. M. wrote:

Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I
adjust
the Red control in the control panel, the color does not shift at
all).

Does this sound like something that could be fixable? Otherwise
I'll
just live with my error, as there is no return possible (everything
sold "as-is")

Thanks in advance,

Dan M.
danmont@umiich.edu.nospam


Every time I've seen a missing color on a 21" Viewsonic it has been
caused by a bad video driver IC. It ususally fails because they
didn't
use any silicone heat sink compound between the IC and the heat sink.
This part costs about $50-$100 and is only worth replacing if the
monitor looks perfect otherwise. It's not that hard to replace, but
the
cost is more than a 21" monitor is worth in my area. What's the
number
of the IC on the big heat sink on the circuit board that's plugged
directly into the CRT? Also, what's the model number? One of the ICs
that caused all the problems was an EY07P, but there were other types
that also tended to fail.
--
Andy Cuffe
baltimora@psu.edu
Click to expand...
 
On Thu, 25 Sep 2003 01:05:38 -0700 "Vector Viper" <ahowald@w-link.net>
wrote in Message id: <vn59g1ag7p9f93@corp.supernews.com>:

"D. M." <danmont@umich.edu.nospam> wrote in message
news:06i3nv08vfpm6bdb1u518t84dmn6ht7jm2@4ax.com...
Hello,

I just purchased a used Viewsonic 21" monitor. I only checked it to
be sure it worked before I purchased it, but when I got it home I
realized that the greenish-blue color cast could not be adjusted out
of it. The Red component does not seem to be present. (When I adjust
the Red control in the control panel, the color does not shift at
all).

Try jumpering the green output to the red one AT THE TUBE CATHODES. you
should get yellow for
any green input-this proves tube good. Or, ground red tube pin, turn on
monitor,
should get red screen (do not run long like this!!!!)
Bad solder on tube sockets also common...
Click to expand...
Isn't there a chance of blowing the green driver circuit when attempting
this? Especially so if the red circuit is shorted to ground, I would
think.
 
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