'cade trouble shooting

[Doc Thirst]

OK a couple of disclaimers...

Sorry again if this is in the wrong forum (don't see a trouble shooting forum)
Sorry for my ignorance

OK I mentioned before that I had a good lead on a hydro-thunder.  Turns out my good lead turned into my bosses good lead.  Doing what every good yes man might do, I offered to help him fix it, and failing to do so said I would "haul it off" if we couldn't get it up.  Now I know you are all thinking sabotage...but I think I'll do what I can, and try and score a raise out of it.

As I mentioned, for a while you get video and sound, then the video dies (20 min or so), but you are left with sound.  After a few months of this the video dies all together, and the service man is called.  Then the process starts again.  The service man isn't returning phone calls (assuming he is a bit bent out of shape for not getting to "haul it off" himself), so we are on our own.

When you hook a reg. computer monitor up directly to the video card on the mb the game runs fine.  The vid card and a 9pin serial from the mb both run to a separate card (analog converter???) then that card has one line to the monitor.

Question 1:
Is there anyway aside from a multimeter or test lite to verify power is getting to a monitor?

Question 2:
What is the 9 pin serial for?

Question 3:
Am I right in assuming that second card is an analog converter?

Question 4:
Is it uncommon for "analog" cards to fail?