Viewsonic E790 With Undocumented Features

N

Nate Smith

Guest
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or waking
up from low power mode... picture randomly expanding/shrinking by 5 or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
 
Flyback
joe

Nate Smith wrote:
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or waking
up from low power mode... picture randomly expanding/shrinking by 5 or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
Click to expand...
 
Yes, poor power supply regulation, probably due to bad caps.

"Nate Smith" <johnsonn@prexar.com> wrote in message
news:0261pvcsvboed4itav1q54k089k47e3hqu@4ax.com...
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or
waking
up from low power mode... picture randomly expanding/shrinking by 5
or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
Click to expand...
 
Poor power supply regulation due to some components starting to fail, many
times be a number of capacitors. This type of symptom can also be attributed
to poor high voltage regulation as well. The primary power supply must be
verified first.

--

Greetings,

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


"Nate Smith" <johnsonn@prexar.com> wrote in message
news:0261pvcsvboed4itav1q54k089k47e3hqu@4ax.com...
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or waking
up from low power mode... picture randomly expanding/shrinking by 5 or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
 
"Spudley" <antispam@bigpond.net.au> wrote in message
news:gZ3kb.155566$bo1.122114@news-server.bigpond.net.au...
Yes, poor power supply regulation, probably due to bad caps.

"Nate Smith" <johnsonn@prexar.com> wrote in message
news:0261pvcsvboed4itav1q54k089k47e3hqu@4ax.com...
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or
waking
up from low power mode... picture randomly expanding/shrinking by 5
or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
Click to expand...
Does just the horizintal width expand? If so replace the 4N35 optoisolator
in the power supply before it takes out the vertical output chip. If this is
the same guts as the PF series this is a very common problem. I've used a
4N26 as a replacement a few times as it's all I had and it worked fine.
 
On Sat, 18 Oct 2003 07:21:07 GMT, "James Sweet"
<jamessweet@hotmail.com> wrote:

"Spudley" <antispam@bigpond.net.au> wrote in message
news:gZ3kb.155566$bo1.122114@news-server.bigpond.net.au...
Yes, poor power supply regulation, probably due to bad caps.

"Nate Smith" <johnsonn@prexar.com> wrote in message
news:0261pvcsvboed4itav1q54k089k47e3hqu@4ax.com...
This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or
waking
up from low power mode... picture randomly expanding/shrinking by 5
or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate



Does just the horizintal width expand? If so replace the 4N35 optoisolator
in the power supply before it takes out the vertical output chip. If this is
the same guts as the PF series this is a very common problem. I've used a
4N26 as a replacement a few times as it's all I had and it worked fine.
Click to expand...
Nope, its vertical also.. which is what led me away from deflection
issues...

Nate
 
Will an ESR meter check caps in circuit? Where can I get a good one
without breaking the bank?

Nate

On Fri, 17 Oct 2003 21:35:57 -0400, Nate Smith <johnsonn@prexar.com>
wrote:

This moniter appears to have developed a zoom function, i dont know
exactly what else to call it, esp when it is turned of cold or waking
up from low power mode... picture randomly expanding/shrinking by 5 or
10 percent... whats your take on this? power supply regulation? bad
caps?

Thanks
Nate
Click to expand...
 
"Nate Smith" <johnsonn@prexar.com> wrote in message
news:4t05pvkl92p7qtlssugb5lc16cttgjkmhl@4ax.com...
Will an ESR meter check caps in circuit? Where can I get a good one
without breaking the bank?

Nate
Click to expand...
Yes it will, I've got the CapWizard that I've been happy with, but the Dick
Smith one is a lot cheaper and supposedly pretty good, I just hadn't heard
of it at the time.

You should still check the power supply, pick an output and tack solder a
wire to it and another to ground. Clip a DMM to it and monitor the voltage
while you use the monitor and see if it creeps up.
 
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