sheldonlg wrote:
> I am running Windows 7 with two monitors. The main display is on the
> left and the secondary on the right. I can, of course, drag things
> between them.
>
> What had been happening for the longest time is that after 10 minutes of
> inactivity, it went to sleep and both monitors turned black. If I moved
> the mouse and clicked on on either monitor, they both woke up.
>
> My computer rebooted last night. Now what happens is that while the
> left one stays on, the right one will go to sleep and turn black. This
> happens before 10 minutes. The only way I can get the right hand screen
> again is to turn off that monitor and turn it back on. Then it shows
> again. Clicking in the does nothing.
>
> Does anyone have any idea on what I have to do to get back to where it
> was before the reboot?
>
Is there any chance it is a problem with that monitor itself ?
If you use that monitor with a second computer, does it stay running
or turn off ?
*******
It could be, that the backlight is turning off and the monitor logic
and LCD panel are still running. LCD monitors have two types of lighting,
either LED or CCFL. And the CCFL type use an "inverter" board. If the
inverter shuts off, then the screen goes black, but the LCD pixels
themselves are still being controlled as before. The only way to see
the image then, is to provide another source of (transmitted) illumination.
Reflective illumination (from the front) may not be enough.
When an inverter shuts off several minutes after startup, one
temporary solution, is to turn down the screen intensity. Then
it may remain running for longer. The reason that works, is it
reduces the load on the inverter, and it stays running longer.
A permanent solution, is to replace the inverter, but that's easier
said than done. The problem is, many companies will sell "equivalent"
replacements but not "exact" replacements. Sometimes those replacements
work, and sometimes they're no better than the broken original.
The CCFL tubes are thin glass rods with electrodes on the end. They're
rated for perhaps 25,000 hours of operation. The inverter should
really last forever, but it seems that typically the inverters
fail before their time. The inverter converts a low voltage DC
(like, say, 12V), into 700-1000VAC at relatively low power (about
3 watts per CCFL tube). The inverters are either transformer
based or piezoelectric based.
(Inverter boards for CCFL tubes)
http://www.powercome.com.tw/INVERTER/2LAMPS.JPG
(Inverter connected to a CCFL tube)
http://computer-repair-naperville.co...-backlight.jpg
If you determine it is the monitor, and you decide to take
the panel apart, remember to put all foil items back the way
you found them. Sometimes, they influence how the thing works,
and aren't just arbitrarily thrown in there.
Paul
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