On Tue, 17 Jun 2008 00:38:41 -0500, jakdedert
put finger to keyboard and composed:

It contains a (socketed) Winbond W78E56P-40. I pulled up the data sheet
for that, but it's beyond my experience to decipher how this generic
processor is employed in the circuit.

That's the microcontroller and firmwa
http://www.datasheetarchive.com/pdf/3655561.pdf

The other large scale (100 or so
leads) chip has a logo that looks like a backward capital 'N' with
numbers MST9111. Google drew a blank on that one.

It's a single-chip LCD Controller for SXGA LCD Monitors by MStar
Semiconductor:
http://www.sacg.com.tw/sacweb/marcom...Fs-new/MST.pdf

The PDF contains a functional block diagram of the chip but no
details. :-(

There are no datasheets on the MStar web site, either, only an email
address:
http://www.mstarsemi.com/products/

FWIW, the MST chip appears to be the one that interfaces to your DB-15
connector. The OSD appears to be generated within it as well. I'd be
looking around there. Maybe check its supply rails, caps, crystal?

I'm not sure what would happen if the host microcontroller (Winbond)
were to fail. If the monitor still responds to the front controls,
then I would think that the Winbond chip is working, or at least not
totally brain dead. I wonder if you would still get anything on your
screen (eg an error OSD) if you were to remove the Winbond chip. Might
be worth trying ...

Changing video resolution makes no difference (refresh was initially 60
Hz anyway). The OSD, when accessed while 'in symptoms', is just a blue
smear up the entire height of the display.

I would compare the OSD in the presence of H&V sync input with the OSD
in the absence of an input. In the latter case the MStar chip would
have to rely solely on the crystal for its reference, whereas in the
former case it would be generating a pixel clock by using its internal
PLL to multiply the H sync frequency.

Any video input to the
display is likewise; all columns and no rows. Each column of pixels is
uniform in color from top to bottom, although that color changes with
the video content. Occasionally horizontal bands will appear, either a
lighter or darker shade...sometimes only a pixel wide, other times wider.

(I wonder if I could record and post a short video somewhere?)

Youtube?

For the last day or so, I've not been able to get any sort of legible
display. I hooked it up to a spare computer, on screensaver, next to my
desk, hoping to catch it actually working...turn it on occasionally for
short periods.

You might be able to tell that I'm not too familiar with the innards of
lcd displays g.

Ditto. Maybe we can both learn something. :-)

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.