TROUBLESHOOTING GUIDE
TROUBLESHOOTING GUIDE
4
Section
10
Trouble
Troubleshooting Tip
Unable to set Vertical Size
The
Vertical Size
value is limited by what values are set for
Frequency
and
Horizontal size
.
Not all video modes can be shown full screen.
Sometimes the vertical size will have to be small.
Cannot Set Correct Frequency
On some systems there are no pictures available that make
frequency setting easy. This can make it very hard to see
what is happening on the screen.
Tip One:
Adjust the
frequency fine
.
When this adjusted any vertical frequency bands on the
screen will move. This makes them much easier to see
- especially if they have been hiding in blank parts of
the display.
Tip Two:
If there are any specifications for the system then you
may be able to calculate what the approximate value of
frequency
should be.
The
frequency
value to set on the monitor is the
TOTAL number of pixels in one horizontal period.
Example:If the Horizontal Line Frequency = 25kHz
Dot Clock = 10mHz
Then
frequency =
10mHz
·/· 25khz
= 400
OR: If 80 characters per line an 12 x 16 character cell
And 35us horizontal active time
And 40us horizontal scanning time
Then
frequency
= 80 x 12 x 35 / 40 = 840
Using calculations like this should make it easy to preset the
frequency into roughly the correct range, but further
adjustment normally will be needed for the last few percent.
Menu button does not work
The OSD lockout feature is enabled.
Hold menu button in for several seconds.
TROUBLESHOOTING GUIDE
If these tips do not solve your problem, contact VarTech Systems Customer Service Support.
