Samsung TFT 204b: extreme slow response
 

Dear all,

My Samsung 204B has a *very* long response time, black-white several
secs.. white-black ~0.5 sec. This happened instantly while in
operation, and persists ever since. Happens both on DVI and VGA, with
different graphic cards (NVIDIA GF 7600GS and ATI 7500) as well as
without any signal input at all, then showing the wandering "Check
signal cable" window. I opened the case, the caps look OK to me, no
bulging or leaking.

Here's a video showing the slow response. The graphics should be
updated instantly. Instead, it appears more like a fade-in
http://www.youtube.com/watch?v=8tcwLBV3jxs

Any hints are greatly appreciated.
Thomas

Samsung TFT 204b: extreme slow response
 

On Tue, 13 Apr 2010 02:01:11 -0700 (PDT), thomas albrecht
wrote:

Dear all,

My Samsung 204B has a *very* long response time, black-white several
secs.. white-black ~0.5 sec. This happened instantly while in
operation, and persists ever since. Happens both on DVI and VGA, with
different graphic cards (NVIDIA GF 7600GS and ATI 7500) as well as
without any signal input at all, then showing the wandering "Check
signal cable" window. I opened the case, the caps look OK to me, no
bulging or leaking.

Here's a video showing the slow response. The graphics should be
updated instantly. Instead, it appears more like a fade-in
http://www.youtube.com/watch?v=8tcwLBV3jxs

Any hints are greatly appreciated.
Thomas

Did you try a different monitor to eliminate any possibility it is GUI
effects from Winders?

Samsung TFT 204b: extreme slow response
 

On Apr 13, 11:01*am, thomas albrecht
wrote:
Dear all,

My Samsung 204B has a *very* long response time, black-white several
secs.. white-black ~0.5 sec. This happened instantly while in
operation, and persists ever since. Happens both on DVI and VGA, with
different graphic cards (NVIDIA GF 7600GS and ATI 7500) as well as
without any signal input at all, then showing the wandering "Check
signal cable" window. I opened the case, the caps look OK to me, no
bulging or leaking.

Here's a video showing the slow response. The graphics should be
updated instantly. Instead, it appears more like a fade-inhttp://www.youtube.com/watch?v=8tcwLBV3jxs

Any hints are greatly appreciated.
Thomas

Does the same happen once you are logged in? Did you try the monitor
on another computer (i.e. e.g. without GRUB)?

Samsung TFT 204b: extreme slow response
 

Thank you for your replies!

Does the same happen once you are logged in? Did you try the monitor
on another computer (i.e. e.g. without GRUB)?
Yes, same effect during POST, OS booting, logged in (text mode), and
GUI running.
Connecting the faulty monitor to another machine did not help.

Did you try a different monitor to eliminate any possibility it is GUI
effects from Winders?
If I connect another monitor to my primary machine, everything shows
up fine, so it's definitely a problem with the monitor itself.

Samsung TFT 204b: extreme slow response
 

On Apr 13, 4:32*pm, thomas albrecht wrote:
Connecting the faulty monitor to another machine did not help.
Why? If it still shows as faulty if you connect it to another machine,
it is clearly a monitor problem.

Samsung TFT 204b: extreme slow response
 

Connecting the faulty monitor to another machine did not help.
Why? If it still shows as faulty if you connect it to another machine,
it is clearly a monitor problem.
Of course you're right. I just wanted to express that my problem with
this monitor persists, even when I connect it to another machine. So
it's not a problem with that specific machine or graphics card or
such.

Samsung TFT 204b: extreme slow response
 

Why? If it still shows as faulty if you connect it to another machine,
it is clearly a monitor problem.
And I didn't mean to say your post wouldn't be helpful, of course!

Samsung TFT 204b: extreme slow response
 

Hi!

It sounds like a signal processing problem. While I doubt that it will
help, have you tried just unplugging the monitor from power and
letting it sit for a while?

Anywhere from several hours to overnight would do. It doesn't cost
anything to try...

William

Samsung TFT 204b: extreme slow response
 

On Apr 13, 4:58*pm, thomas albrecht wrote:
Why? If it still shows as faulty if you connect it to another machine,
it is clearly a monitor problem.

And I didn't mean to say your post wouldn't be helpful, of course!

No problem, Thomas. I was tired ;-).

Trying William's suggestion does no harm, and that could be tried. In
such situations, anything needs to be tried, particularly the obvious.

Habitually, TFTs monitors do or do not work. I mean... you turn them
on, and either everything's right or nothing works. That is my point
of view, but I am not the only one to preach in this.

Samsung TFT 204b: extreme slow response
 

Hi William!

have you tried just unplugging the monitor from power and
letting it sit for a while?

Thanks for your suggestion! Actually, it has been sitting powered off
& disconnected for several months after it broke. I only recently
leaned about the many problems with bulging capacitors of this
particular TFT, so I decided to give it a try and look inside. The
youtube video, however, I took just the other day, so, unfortunately,
this seems to be more like a long-term problem...

Thomas

Samsung TFT 204b: extreme slow response
 

Hi William!

have you tried just unplugging the monitor from power and
letting it sit for a while?

Thanks for your suggestion! Actually, it has been sitting powered off
& disconnected for several months after it broke. I only recently
leaned about the many problems with bulging capacitors of this
particular TFT, so I decided to give it a try and look inside. The
youtube video, however, I took just the other day, so, unfortunately,
this seems to be more like a long-term problem...

Thomas

Samsung TFT 204b: extreme slow response
 

Hi William!

have you tried just unplugging the monitor from power and
letting it sit for a while?

Thanks for your suggestion! Actually, it has been sitting powered off
& disconnected for several months after it broke. I only recently
leaned about the many problems with bulging capacitors of this
particular TFT, so I decided to give it a try and look inside. The
youtube video, however, I took just the other day, so, unfortunately,
this seems to be more like a long-term problem...

Thomas

Samsung TFT 204b: extreme slow response
 

On 13 Abr, 11:01, thomas albrecht wrote:
Dear all,

My Samsung 204B has a *very* long response time, black-white several
secs.. white-black ~0.5 sec. This happened instantly while in
operation, and persists ever since. Happens both on DVI and VGA, with
different graphic cards (NVIDIA GF 7600GS and ATI 7500) as well as
without any signal input at all, then showing the wandering "Check
signal cable" window. I opened the case, the caps look OK to me, no
bulging or leaking.

Here's a video showing the slow response. The graphics should be
updated instantly. Instead, it appears more like a fade-inhttp://www.youtube.com/watch?v=8tcwLBV3jxs

Any hints are greatly appreciated.
Thomas

This fade looks so nice it seems a feature instead of a fault. Have
you checked all menu options to ensure some weird option has not been
enabled?

Carefully observing the video reveals that going from white to black
is immediate but the opposite is not. The effect reminds me of a
digital clock with weak battery. It could be some weak voltage from
the power supply, probably a bad capacitor.

Samsung TFT 204b: extreme slow response
 

Hi Jeroni!

This fade looks so nice it seems a feature instead of a fault. Have
you checked all menu options to ensure some weird option has not been
enabled?
So maybe I should sell this monitor for it has this extremely rare,
special feature? :) Nope, unfortunately, there are no menu options
like that...

It could be some weak voltage from
the power supply, probably a bad capacitor.
OK, thanks for the hint. That model is known for having problems with
capacitors, but commonly described symptoms are different from what I
observe. I'm going to change the capacitors, anyway, and keep you
posted.

Thomas

Samsung TFT 204b: extreme slow response
 

On Tue, 13 Apr 2010 02:01:11 -0700 (PDT), thomas albrecht
wrote:

Dear all,

My Samsung 204B has a *very* long response time, black-white several
secs.. white-black ~0.5 sec. This happened instantly while in
operation, and persists ever since. Happens both on DVI and VGA, with
different graphic cards (NVIDIA GF 7600GS and ATI 7500) as well as
without any signal input at all, then showing the wandering "Check
signal cable" window. I opened the case, the caps look OK to me, no
bulging or leaking.

Here's a video showing the slow response. The graphics should be
updated instantly. Instead, it appears more like a fade-in
http://www.youtube.com/watch?v=8tcwLBV3jxs

Any hints are greatly appreciated.
Thomas
While it isn't obvious, an LCD monitor breaks down into several
electronic sections. Power supply, inverter / backlight, logic
(signal processing) card, and LCD panel.

1. Check the output voltages of the power supply. Yes, I know the
caps look good, but a quick check of the actual voltages MIGHT pickup
a problem.

2. The logic card contains several voltage regulators to provide the
proper voltages for the processor and it's support components, and
often for the LCD panel. These are tyoically a three pin device with
tab. Byu Googling the part number on these devices you can determine
the output voltage. Verify those voltages. While it is unlikely an
incorrect output voltage would cause the symptoms you describe, it's
worth the try.

3. The LCD panel usually contains an electronics card (often conceled
under a metal cover) which generates the voltages and signals
necessary for the proper operation of the panel. I suspect one of
these voltages is missing. This is going to require a LOT of
detective work to analyse, so try the easier stuff first.

PlainBill