I was just gifted with a GD-H4220US monitor that isn't behaving as expected.
My best Web research indicates that it is a 19" analog/digital RGB monitor
(dual 9-pin connectors and a mode switch) with scan rates of 15-37Khz and
45-87 Hz. I have attached this device to an Amiga 3000, my 486 LRP box
and a SPARC2 w/single-width CG6 (via the standard 1395 13W3 adapter). In
no case does this monitor give me a locked, stable display.
The CG6 does the best, but the top dozen lines do not align, giving a "torn"
appearance. The Amiga 3000 (15.75Khz and 31Khz, both) produce at best, two
copies of the video, one on the top half of the screen, one on the bottom
half.
The externally accessible controls are a bank of 4 pots with height,
v alignment, width and h alignment icons, labelled A through D; an overscan
enable switch; a "cancel preset" switch and the usual bright and contrast
controls on the front. I am using two different adapters to convert the
monitor's 9-pin RGB to the more common 15-pin high-density connector used
today for VGA. One adapter is a short cable, source unknown, the other adapter
came with my Amiga 3000. Both adapters produce the same results.
I have color, I have video data. I appear to be lacking in the sync
department.
The only other specs I found on the H4220US is that is is H-V, +ve sync. What
I'm not sure about is how common positive sync is these days (it may be the
standard for all I know; I've seen negative sync stuff in the past) and
whether or not my adapters are properly propogating the sync signals. There
is, of course, the possibility that the monitor is defective, but I suspect
wiring, first.
Can anyone point me to a chart that has the older 9-pin RGB standard? I can
verify my adapter, then. Also, I'm not sure what kind of sync a CG6 generates.
Can someone shed some light there, too? It's a really awesome monitor,
especially for the price. Even with the plastic cover off, it generates no
audible noise, unlike every other monitor in the room. One drawback: 2.3A
listed draw (4A fuse). That's a lotta watts to keep powered on.
I have the covers off at the moment and can find no obvious place to tweak
the sync circuit. The manufacturing date is 1989 and it does not appear to
be microprocessor controlled. Nothing appears obviously smoked or
disconnected.
I do not have any documentation to go with this display.
Thanks in advance,
-ethan
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Received on Mon Feb 07 2000 - 15:59:17 GMT