Viewsonic Vertical Problem

S

Scott Nielson

Guest
I am trying to repair a vertical size and liniarity problem with a Viewsonic
E771. The picture only fills about 75% of the screen and is non linear. It
is squishes and bows a bit toward the top of the picture. I have searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a schematic. I
can stretch it using the OSD controls, but that only fills about 75% of the
screen.

I'm know I'm not the first person to try to fix a problem like this. I find
other reports on the internet of this same model with the same problem.
But, I can't find and reports of what was done to fix it. Has anyone seen
this before? Or can someone give me some more direction?

Thanks.
 
Use an ESR meter and check the capacitors in the vertical deflection
circuit. You may even need to pull them and check all the critical
parameters to find the one that is bad, Value, ESR, leakage, etc.

David

"Scott Nielson" <oct21@xmission.com> wrote in message
news:c7p82d$269$1@terabinaries.xmission.com...
I am trying to repair a vertical size and liniarity problem with a
Viewsonic
E771. The picture only fills about 75% of the screen and is non linear.
It
is squishes and bows a bit toward the top of the picture. I have searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a schematic.
I
can stretch it using the OSD controls, but that only fills about 75% of
the
screen.

I'm know I'm not the first person to try to fix a problem like this. I
find
other reports on the internet of this same model with the same problem.
But, I can't find and reports of what was done to fix it. Has anyone seen
this before? Or can someone give me some more direction?

Thanks.
Click to expand...
 
Scott Nielson wrote:

I am trying to repair a vertical size and liniarity problem with a Viewsonic
E771. The picture only fills about 75% of the screen and is non linear. It
is squishes and bows a bit toward the top of the picture. I have searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a schematic. I
can stretch it using the OSD controls, but that only fills about 75% of the
screen.

I'm know I'm not the first person to try to fix a problem like this. I find
other reports on the internet of this same model with the same problem.
But, I can't find and reports of what was done to fix it. Has anyone seen
this before? Or can someone give me some more direction?

Thanks.
Click to expand...
To your question about has any else seen this problem before: The
answer is "Yes!" I like you, had tried everything I could think of
since this was the ONLY problem with the monitor. After more hours than
I wish to admit to, I tore the monitor apart for parts so that I would
stop going back to it with another idea. It became almost an obsession.
I shall watch this thread to see if you find the problem. Good luck.
 
"user@domain.invalid" bravely wrote to "All" (11 May 04 11:59:45)
--- on the heady topic of "Re: Viewsonic Vertical Problem"

I had a monitor, I forget the brand, with a similar vertical problem
at the top of the display, only to make it more interesting, this one
was intermittant. Turned out to be a zener diode near the vertical IC
which was opening up. Like you I had gone at it a few times and gave
up in frustration but the diode stared out at me one time which then
prompted me to drive it with an external current source to show a high
resistance when the package was moved. Bugger that was it!


us> From: user@domain.invalid

us> Scott Nielson wrote:

I am trying to repair a vertical size and liniarity problem with a Viewsonic
E771. The picture only fills about 75% of the screen and is non linear. It
is squishes and bows a bit toward the top of the picture. I have searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a schematic. I
can stretch it using the OSD controls, but that only fills about 75% of the
screen.

I'm know I'm not the first person to try to fix a problem like this. I find
other reports on the internet of this same model with the same problem.
But, I can't find and reports of what was done to fix it. Has anyone seen
this before? Or can someone give me some more direction?

Thanks.
Click to expand...
us> To your question about has any else seen this problem before: The
us> answer is "Yes!" I like you, had tried everything I could think of
us> since this was the ONLY problem with the monitor. After more hours
us> than I wish to admit to, I tore the monitor apart for parts so that I
us> would stop going back to it with another idea. It became almost an
us> obsession. I shall watch this thread to see if you find the problem.
us> Good luck.

.... You mean 15" sparks are SUPPOSED to come out of this thing?!?
 
Asimov wrote:
"user@domain.invalid" bravely wrote to "All" (11 May 04 11:59:45)
--- on the heady topic of "Re: Viewsonic Vertical Problem"

I had a monitor, I forget the brand, with a similar vertical problem
at the top of the display, only to make it more interesting, this one
was intermittant. Turned out to be a zener diode near the vertical IC
which was opening up. Like you I had gone at it a few times and gave
up in frustration but the diode stared out at me one time which then
prompted me to drive it with an external current source to show a high
resistance when the package was moved. Bugger that was it!
Click to expand...
Interesting!! I shall keep this in mind if I ever see such a problem
again. Hopefully, I will NEVER see this type of problem again.
us> From: user@domain.invalid

us> Scott Nielson wrote:

I am trying to repair a vertical size and liniarity problem with a Viewsonic
E771. The picture only fills about 75% of the screen and is non linear. It
is squishes and bows a bit toward the top of the picture. I have searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a schematic. I
can stretch it using the OSD controls, but that only fills about 75% of the
screen.

I'm know I'm not the first person to try to fix a problem like this. I find
other reports on the internet of this same model with the same problem.
But, I can't find and reports of what was done to fix it. Has anyone seen
this before? Or can someone give me some more direction?

Thanks.



us> To your question about has any else seen this problem before: The
us> answer is "Yes!" I like you, had tried everything I could think of
us> since this was the ONLY problem with the monitor. After more hours
us> than I wish to admit to, I tore the monitor apart for parts so that I
us> would stop going back to it with another idea. It became almost an
us> obsession. I shall watch this thread to see if you find the problem.
us> Good luck.

... You mean 15" sparks are SUPPOSED to come out of this thing?!?
Click to expand...
 
Well, I replaced almost everything in the vertical circuit and the vertical
problem didn't go away. So, we'll be replacing this montior with a new LCD
monitor.

<user@domain.invalid> wrote in message
news:8Jnoc.83084$Xj6.1390020@bgtnsc04-news.ops.worldnet.att.net...
Asimov wrote:
"user@domain.invalid" bravely wrote to "All" (11 May 04 11:59:45)
--- on the heady topic of "Re: Viewsonic Vertical Problem"

I had a monitor, I forget the brand, with a similar vertical problem
at the top of the display, only to make it more interesting, this one
was intermittant. Turned out to be a zener diode near the vertical IC
which was opening up. Like you I had gone at it a few times and gave
up in frustration but the diode stared out at me one time which then
prompted me to drive it with an external current source to show a high
resistance when the package was moved. Bugger that was it!

Interesting!! I shall keep this in mind if I ever see such a problem
again. Hopefully, I will NEVER see this type of problem again.


us> From: user@domain.invalid

us> Scott Nielson wrote:

I am trying to repair a vertical size and liniarity problem with a
Viewsonic
E771. The picture only fills about 75% of the screen and is non
linear. It
is squishes and bows a bit toward the top of the picture. I have
searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a
schematic. I
can stretch it using the OSD controls, but that only fills about 75%
of the
screen.

I'm know I'm not the first person to try to fix a problem like this.
I find
other reports on the internet of this same model with the same
problem.
But, I can't find and reports of what was done to fix it. Has anyone
seen
this before? Or can someone give me some more direction?

Thanks.



us> To your question about has any else seen this problem before: The
us> answer is "Yes!" I like you, had tried everything I could think of
us> since this was the ONLY problem with the monitor. After more hours
us> than I wish to admit to, I tore the monitor apart for parts so
that I
us> would stop going back to it with another idea. It became almost
an
us> obsession. I shall watch this thread to see if you find the
problem.
us> Good luck.

... You mean 15" sparks are SUPPOSED to come out of this thing?!?
Click to expand...
 
I've been monitoring this post for a few days, and wonder if it relates to
my problem. My ViewSonic E790, does something messed up. I contacted
ViewSonic, and they said it was because it need more of a dedicated power
source, because of the size of the monitor. What it does, is the screen
shrinks. It's a 19" (18" viewable), that will shrink to about 15". The
actually video, not the whole monitor..:) There will be about 1.5" black
around the whole video. You can even use the OSC and widen it back out.
However, after it get's done "Throwing it's little Fit", and returns back to
it's original size, you have to resize it back, or the screen is too big too
see around the edges. The screen also gets really bright. Most of the
time, it "flickers" like the above stated, for about 5-10 minutes, then
returns to normal, and I don't have a problem for a while. Other times, it
will do it for a couple hours at a time. AND on occasion, when it shrinks,
it will turn off. But the green light will stay on like if the monitor is
still active. (Normally the light turns orange, when it goes into stand by)

Now, once again, I contacted ViewSonic when I first noticed this problem.
The said it was because I had too much plugged into the outlet. So I ran a
construction extension cord to an outlet that had nothing plugged into it
(The whole circuit). It stopped for a while (about a month). However, it
started again. But, guess what, it was out of warranty. Now, I moved over
700 miles from where I lived at, and still have the same problem. So I tend
to think that it is in the monitor, ViewSonic was just tiring to get out of
fixing it....

Thanks,
Rick


<user@domain.invalid> wrote in message
news:8Jnoc.83084$Xj6.1390020@bgtnsc04-news.ops.worldnet.att.net...
Asimov wrote:
"user@domain.invalid" bravely wrote to "All" (11 May 04 11:59:45)
--- on the heady topic of "Re: Viewsonic Vertical Problem"

I had a monitor, I forget the brand, with a similar vertical problem
at the top of the display, only to make it more interesting, this one
was intermittant. Turned out to be a zener diode near the vertical IC
which was opening up. Like you I had gone at it a few times and gave
up in frustration but the diode stared out at me one time which then
prompted me to drive it with an external current source to show a high
resistance when the package was moved. Bugger that was it!

Interesting!! I shall keep this in mind if I ever see such a problem
again. Hopefully, I will NEVER see this type of problem again.


us> From: user@domain.invalid

us> Scott Nielson wrote:

I am trying to repair a vertical size and liniarity problem with a
Viewsonic
E771. The picture only fills about 75% of the screen and is non
linear. It
is squishes and bows a bit toward the top of the picture. I have
searched
and searched in the vertical deflection
circuits but have been unable to find a problem. I tested a lot of
components and even replaced a few, but no luck. I do have a
schematic. I
can stretch it using the OSD controls, but that only fills about 75%
of the
screen.

I'm know I'm not the first person to try to fix a problem like this.
I find
other reports on the internet of this same model with the same
problem.
But, I can't find and reports of what was done to fix it. Has anyone
seen
this before? Or can someone give me some more direction?

Thanks.



us> To your question about has any else seen this problem before: The
us> answer is "Yes!" I like you, had tried everything I could think of
us> since this was the ONLY problem with the monitor. After more hours
us> than I wish to admit to, I tore the monitor apart for parts so
that I
us> would stop going back to it with another idea. It became almost
an
us> obsession. I shall watch this thread to see if you find the
problem.
us> Good luck.

... You mean 15" sparks are SUPPOSED to come out of this thing?!?
Click to expand...
 
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