Viewsonic VG800 LCD monitor power problem

  • Thread starter Benjamin Jennings, MCP
  • Start date
B

Benjamin Jennings, MCP

Guest
Hi,

Working without a service manual on this one and have 2 more just like it.
Plug power in and it sorta flickers on and off, power/status LED flickers
different colors several times and finally stabilizes at a stedy flashing
green about once per second and the backlight pulses about the same
frequency. I noticed a myriad of SMD caps and checked most of them for
high ESR, most are pretty decent, a couple are marginal but seem to be
alright. uPC supply voltages seem pretty solid so I'm kinda stumped.
Anybody seen this problem before, being as I have 3 of these all failed near
the same time I'd suspect it's a common problem or soon will be.

Thanks,
Benjamin Jennings, MCP
 
Two things:

One: do they all have the same symptom ? If so have you plugged in a
valid input ?? (to EACH)

Two: if they do not have the same symptom, what are the other symptoms
?

Thinking of it this way can get you down to board level real fast, but
don't rush to sell anything that works, use it as a reference to fix
another.

Happens all the time.

JURB
 
responding to
http://www.electrondepot.com/repair/viewsonic-vg800-lcd-monitor-power-problem-44095-.htm
, SolarAngel wrote:
icesoft wrote:

Hi,

Working without a service manual on this one and have 2 more just like
it.
Plug power in and it sorta flickers on and off, power/status LED
flickers
different colors several times and finally stabilizes at a stedy
flashing
green about once per second and the backlight pulses about the same
frequency. I noticed a myriad of SMD caps and checked most of them
for
high ESR, most are pretty decent, a couple are marginal but seem to be
alright. uPC supply voltages seem pretty solid so I'm kinda stumped.

Anybody seen this problem before, being as I have 3 of these all failed
near
the same time I'd suspect it's a common problem or soon will be.

Thanks,
Benjamin Jennings, MCP
Click to expand...
I have similar behavior but monitor shows screen after several minutes.
Do you by any chance remember what was the problem with this monitors ???
 
On Mon, 03 Dec 2012 15:18:02 +0000, SolarAngel
<f6ceedb9c75b52f7fcc0a55cf0cfbf5d_906@example.com> wrote:

responding to
http://www.electrondepot.com/repair/viewsonic-vg800-lcd-monitor-power-problem-44095-.htm
, SolarAngel wrote:
icesoft wrote:

Hi,

Working without a service manual on this one and have 2 more just like
it.
Plug power in and it sorta flickers on and off, power/status LED
flickers
different colors several times and finally stabilizes at a stedy
flashing
green about once per second and the backlight pulses about the same
frequency. I noticed a myriad of SMD caps and checked most of them
for
high ESR, most are pretty decent, a couple are marginal but seem to be
alright. uPC supply voltages seem pretty solid so I'm kinda stumped.

Anybody seen this problem before, being as I have 3 of these all failed
near
the same time I'd suspect it's a common problem or soon will be.

Thanks,
Benjamin Jennings, MCP

I have similar behavior but monitor shows screen after several minutes.
Do you by any chance remember what was the problem with this monitors ???

Check with the folks at www.badcaps.net/forum
Click to expand...

PlainBill
 
<PlainBill@yawhoo.com> wrote in message
news:idppb8pa51he7g3oat9lcoh21pds5d9fee@4ax.com...
On Mon, 03 Dec 2012 15:18:02 +0000, SolarAngel
f6ceedb9c75b52f7fcc0a55cf0cfbf5d_906@example.com> wrote:

responding to
http://www.electrondepot.com/repair/viewsonic-vg800-lcd-monitor-power-problem-44095-.htm
, SolarAngel wrote:
icesoft wrote:

Hi,

Working without a service manual on this one and have 2 more just like
it.
Plug power in and it sorta flickers on and off, power/status LED
flickers
different colors several times and finally stabilizes at a stedy
flashing
green about once per second and the backlight pulses about the same
frequency. I noticed a myriad of SMD caps and checked most of them
for
high ESR, most are pretty decent, a couple are marginal but seem to be
alright. uPC supply voltages seem pretty solid so I'm kinda stumped.

Anybody seen this problem before, being as I have 3 of these all failed
near
the same time I'd suspect it's a common problem or soon will be.

Thanks,
Benjamin Jennings, MCP

I have similar behavior but monitor shows screen after several minutes.
Do you by any chance remember what was the problem with this monitors ???

Check with the folks at www.badcaps.net/forum

PlainBill
Click to expand...

Replacing caps fixed my Viewsonic - watching it right now.

Mark Z.
 
On Tue, 4 Dec 2012 07:22:40 -0600, "Mark Zacharias"
<mark_zacharias@labolgcbs.net> wrote:

PlainBill@yawhoo.com> wrote in message
news:idppb8pa51he7g3oat9lcoh21pds5d9fee@4ax.com...
On Mon, 03 Dec 2012 15:18:02 +0000, SolarAngel
f6ceedb9c75b52f7fcc0a55cf0cfbf5d_906@example.com> wrote:

responding to
http://www.electrondepot.com/repair/viewsonic-vg800-lcd-monitor-power-problem-44095-.htm
, SolarAngel wrote:
icesoft wrote:

Hi,

Working without a service manual on this one and have 2 more just like
it.
Plug power in and it sorta flickers on and off, power/status LED
flickers
different colors several times and finally stabilizes at a stedy
flashing
green about once per second and the backlight pulses about the same
frequency. I noticed a myriad of SMD caps and checked most of them
for
high ESR, most are pretty decent, a couple are marginal but seem to be
alright. uPC supply voltages seem pretty solid so I'm kinda stumped.

Anybody seen this problem before, being as I have 3 of these all failed
near
the same time I'd suspect it's a common problem or soon will be.

Thanks,
Benjamin Jennings, MCP

I have similar behavior but monitor shows screen after several minutes.
Do you by any chance remember what was the problem with this monitors ???

Check with the folks at www.badcaps.net/forum

PlainBill


Replacing caps fixed my Viewsonic - watching it right now.

Mark Z.
Thaat is a common problem. However I didn't feel like explaining ESR,
Click to expand...
explaining why the caps he could buy in a $5.00 bag at Radio Shack
weren't good enough, why spending a few bucks less and waiting a
couple of days for delivery was a good idea, and above all trying to
troubleshoot without pictures.

PlainBill
 
responding to
http://www.electrondepot.com/repair/viewsonic-vg800-lcd-monitor-power-problem-44095-.htm
, SolarAngel wrote:
I know about bad capacitors, but wanted to know for sure is this common
problem with all ViewSonic models, and does it result in this kind of problem
- waiting for several minutes for screen to light up.

have found service manual for my model on net, and wondering to replace bad
caps my self.
but also was wondering to replace bad caps with little higher voltage
capacitors.
for example 50uF 20V to replace with 50uF 40V.
could this produce some problems or to go with this plan!?

but first need new monitor (how else to read service manual),
and funny thing I have found exactly same model for free,
only difference second one was sitting 5 years in box LOL
need only to drive to uncle to get it ;)
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top