Either the macbook is driving it outside its range (but just barely)
or the monitor itself isn't sensing the clock and auto-synchronizing
appropriately.

You can try a few different refresh rates to see if you can find one
the monitor is happier with on wake up.  You might see this if, for
instance, the monitor is expecting 60Hz and the macbook is feeding
59.94Hz or vice versa - the monitor thinks it's in the right range,
but it's not, and it takes awhile to shift out of phase enough before
it does an autoadjust.

The monitor may also have a method to force and auto adjust, where it
will blank the screen and look at the signal carefully for a few
seconds before synchronizing to the signal again.  You may be able to
find the monitor manual online, and it may only be one button press
and hold.

Also, make sure you're driving it at its exact resolution - I've found
some LCD monitors adjust faster if you drive them at their native
resolution, although in theory it shouldn't make a difference.

On Thu, Nov 26, 2009 at 2:22 PM, YES NOPE9 <yes@nope9.com> wrote:
> I have an 19 inch LCD display I got for $5 at a junkyard. =A0I hacked
> together a 24V 2A supply for it. =A0 It works fine except.......
> It is a second monitor for my MacBook. =A0When my MacBook goes to sleep,
> the display goes black. =A0When I wake my MacBook up, often the extra
> display is torn horizontally. =A0The right and left edges have jagged
> edges with a periodicity of about 4 mm. =A0 At first I would turn the
> display on and off and eventually it would stabilize. =A0 Then I
> accidently noticed that if I left it alone for 90 seconds .... the
> jags would get larger in periodicity and eventually would reach about
> 20 cm at which point the display stabilizes.
>
> What might be causing this behaviour ?
>
> Gus
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