Have a HP DC7100 sff pc running XP and connected to it is a Matrox G550 Low profile PCI graphics card running twin NEC 1880sx LCD screens.

There seems to be an inconsistant issue whereby if you connect the screens up via the DVI-D terminals from a DVD-D cable from the PC the screens will work fine until you reboot the machine a couple of times, the screens then do not start and when you switch them on manually they come up with a sign that non of the DVI sockets or D Sub sockets have a signal.

Any ideas ?

It now appears that the issues is with the LCD NEC monitors. If you setup the monitors with D sub inputs this works fine. Then shut down the PC but do not switch off the monitors and replace the D Sub with DVI and power the PC up again and this is fine. If at any time you switch the monitors off and reboot the PC with the DVI cables in the montors respond by telling you no DVI or D sub signal is present :confused:

Hmm not sure about that one. If you have another pair of DVI-capable monitors to try, replacing the NEC ones, may be worth a test.

If the Matrox card is still "configured" for the dual-head setup when you don't get any picture up on the screen, I'd suggest it's the monitors more than the card / drivers / OS.

Actually, worth looking at what you get in the display properties when the monitors are saying no DVI connection. Is the OS reporting the monitors correctly?

X ,

The monitors are being picked up by windows if I load the driver. I have spoken to NEC and they have got an engineer working on it. I have tried about 8 pairs of NEC monitors and they all have the same issue. I suggest NEC may have to update the firmware as it's something to do with signal detection on the monitors as the matrox card is working faultlessly

Just had a phone call back from NEC and this is a known issue LOL

Well after speaking to NEC again it was found that a sertain level of firmware is at fault. I found a set of screens with a later firmware version and these worked fine. Looks like NEC will be replacing about 200 screens in our building.