I have tried to connect two different monitors to a CPU. A LG Flatron L1915S that just goes into power saving mode when started and a Samsung syncmaster 225bw that gives a message "check cable". Both monitors work on other CPUs. The current CPU does not have a VGA connection. With an adaptor I can connect a VGA or a DVI cable (Flatron only have VGA possibility). I guess the problem is in the CPU but how can I troubble-shoot? Is it the graphics card (how do I check that?) or can I somehow adjust the monitors to accept the signal from the CPU?