3Dlabs Wildcat VP 990 Pro / AG Neovo X-19 NO SIGNAL
I have the 3dlabs VP 990Pro graphic card which has two graphic apapters with two DVI-I female connectors (and a 3pin stereo sync connector which is insignificant for the issue). If I use the DVI to analog adapter supplied with the card, and standard 15-pin VGA cable, the AG Neovo X-19 monitor works fine, if I use the DVI cable supplied with the monitor, I get the the 'no signal' message.
I found it not possible to change the input from the OSD on the monitor, because it obviously automatically detects whether there is a signal on any of the inputs, and when there is no signal, it (the OSD menu) does not provide a possibility to switch the input to the "wanted" one.
I came to the idea (same as bruckshaw) of connecting both cables i.e. the 15 pin D-SUB via DVI to analog adapter on one DVI connector on the card and DVI cable on the other connector, but nothing happened i.e. regardless of which of the two graphic adapters (connectors) on the card I was trying to use, both will work only with the DVI to analog adapter i.e. monitor gets only the analog signal.
So, I concluded that most likely the cable supplied with the monitor is not good (although it should be) or that the (automatic) detection of input signal on the monitor is not working. I still have not had time to deal with the issue (all this happened last night) and will appreciate any clever advice (of course, will send a memo to 3dlabs as soon as I retreive the information needed to get the right for a technical support)