Customer buys a new computer, but continues using the old monitor (a HP FW660AA).

Since the new PC has a DVI plug, I decide to connect the monitor using DVI (previously it was using the analog VGA cable).

Everything works well for about a day, and then I’m told the monitor say “going to sleep” and then goes blank. No matter what buttons are pressed, it just goes blank.

I ask the customer to use the VGA cord, and everything is OK, but I’m soon told that the display is “wavy”.

I go out thinking its probably something strange with the standby settings, or maybe the BIOS needs updating.

I get there, and I find restarting the PC fixes the problem, but I can force the problem to occur by setting the XP power properties to “system standby” in 1 minute, and then waiting 1 minute.

Sure enough, after 1 minute, the system goes to standby, and the system seems to be “off”. I move the mouse, and the system resumes, the HDD light flickers, but the monitor remains dark.

Oddly, this is not a problem while using the VGA cable.

OK, I download and install the latest intel motherboard BIOS, but that doesn’t help.

Since the customer has a spare Dell S2009Wb monitor, I plug it in, and I find it works perfectly using the DVI cable/plugs… and more importantly, it resumes from standby correctly.

So the HP monitor had a very specific fault: Only while using DVI, if the DVI signal indicated “go to standby” the monitor would shut down, and then be unable to detect when the DVI signal was available again…. weird.