On Thu, 23 Mar 2006 14:56:32 GMT, "Scrim" wrote:

In the GDM-F520 Service Manual (page 3-5) is a diagram showing the "FBT"
with two knobs marked "Focus 1" & "Focus 2". Is that one each for Horizontal
& Vertical focus? If so , I wouldn't mind betting that the pot track contact
is playing up. If not, are there pots elsewhere?
I'm really keen to keep this monitor running for a few year, not just to get
my monies worth (important), but because I doubt I'll replace it with
anything as good! It's only thanks to everyone changing over to panel
screens that the opportunity to own a top of the range monitor like this has
come my way.Thank you progress! It's ironic that it turns out the top of the
range monitor has serious design flaws! Sony! Hang your heads in shame! Dig
out your Samurai Swords, or apologise and do your best to remedy the
situation (with information if nothing else)!
Scrim



Yes, those are the horizontal and vertical focus knobs. One affects
both almost equally and the other mostly affects the horizontal. It's
worth running both controls through their entire adjustment range a
few times just in case it is a dirty pot or something.

Display a pattern of white vertical lines and adjust the horizontal
for the thinnest vertical lines. Don't forget to look at the extreme
right and left edges because a small misadjustment can make the edges
extremely blurry. The correct setting will be a compromise between
the edges and center. Next display some thin horizontal lines and
adjust the vertical focus for the thinnest horizontal lines. Also be
sure the check the top and bottom focus as well as the center. Go
between them a few times and finish on the vertical focus so the
raster lines are as sharp as possible. That's not the official
adjustment procedure, but I've found it produces the best results.

These are very nice monitors, but they have their share of problems.
The other common problem is that the brightness tends to increase as
the CRT ages. Eventually it gets so bright that it can't produce
black at all. The official fix is to use the alignment software to do
a complete grayscale adjustment. This requires software and
equipment not available to most people. There is a resistor that can
be changed to reduce the G2 voltage. Later models could correct this
problem using the color return feature, but I don't think the F520
can.
Andy Cuffe