Norwood Micro 19" DVI doesn't work?

[eccerr0r]

I wonder if anyone has seen something like this:

I have an old 19" Norwood Micro LCD (4:3! yay!) and Analog VGA works perfectly fine. However if I try to use DVI, it doesn't work and I don't recall it ever working because I never had a DVI output till now. I haven't had to use the DVI port because I now have other monitors whose DVI ports work, but if this monitor's DVI port worked it would make things much easier...

Could a bad capacitor cause DVI not to work but Analog work just fine?

Maybe something else is wrong?

[Davi.p]

Re: Norwood Micro 19" DVI doesn't work?

I don't think is a badcaps related probl., unfortunately i dont have a solution, then try to access factory settings menu by in off state hold pressed 2 of the buttons then push power, usually there is nothing useful in that menu, try to do a time reset, an user setting reset, check all the double diodes on the connector data lines, more of this i don't know..

[lexwalker]

Re: Norwood Micro 19" DVI doesn't work?

I wonder if anyone has seen something like this:

I have an old 19" Norwood Micro LCD (4:3! yay!) and Analog VGA works perfectly fine. However if I try to use DVI, it doesn't work and I don't recall it ever working because I never had a DVI output till now. I haven't had to use the DVI port because I now have other monitors whose DVI ports work, but if this monitor's DVI port worked it would make things much easier...

Could a bad capacitor cause DVI not to work but Analog work just fine?

Maybe something else is wrong?

First of all, did you try changing the input selection to DVI port (via the monitor control buttons)? Certainly does not sound like a badcap problem. If changing the input selection does not work then you have to start checking the area around the DVI port. Start off with those ESD protection diodes on the signal lines. Sometimes there's a resistor in series, thus check them as well...

[Lumberjack777]

Re: Norwood Micro 19" DVI doesn't work?

That's great advice Lex. Sometimes it's as simple as setting the monitor to detect DVI input.
Another possibility is what is known as EDID corruption. It's rare but it does happen. There's a few good articles on the internet for fixing it. Here's an example....
http://blog.komeil.com/2008/06/fixin...no-signal.html

[eccerr0r]

Re: Norwood Micro 19" DVI doesn't work?

I just found out in parallel that it's likely EDID indeed. I did notice as Linux tried to read EDID information, it said it was corrupt. However, no dice with attempts at using the "canned" EDIDs, not sure if Linux is actually trying to use them or simply ignoring them due to some obscure bug...

What I finally found:

When I fresh boot the machine with the monitor attached: the default text mode worked! So the DVI port itself has to be fine. All the attempts before I had either let it boot and turned my head away, and noticed it was always stuck, or hotplugged DVI and the machine grabbed the bad EDID and did not know how to deal with it, so the screen remained blank and off.

So now the quest is to use either my working 19" monitor's EDID or use the Linux canned EDID to see if it will wake up the monitor in DVI mode... Thanks that was interesting that EDID can be updated through DVI? I wonder if I can "fix" this for good ...

[Davi.p]

Re: Norwood Micro 19" DVI doesn't work?

If you download a casual monitor's service manual you find useful info maybe, i know edid as well as firmware ca be uploaded at least via VGA..

[eccerr0r]

Re: Norwood Micro 19" DVI doesn't work?

I copied my i-inc 19" LCD EDID to my Norwood, and yay it looks like DVI is working!

Thanks all. It's good to have another DVI monitor working. Now I just need to rearrange my keyboards so I can use both (I wish synergy worked perfectly but it does not...)

I just need to fix this edid so that it at least tells me which monitor is which now...

[Lumberjack777]

Re: Norwood Micro 19" DVI doesn't work?

Excellent news. Good job fixing that

[shovenose]

Re: Norwood Micro 19" DVI doesn't work?

I didn't know EDID could be modified. Interesting!

[Davi.p]

Re: Norwood Micro 19" DVI doesn't work?

You changed EDID with only Linux pc and a vga cable to the graphic card? Because service manuals shows a parrallel port I2C interface to Vga/dvi and a special sw...