Smart DC 330 VGA Input Issue

[UnknownSoundman]

I've got an issue with a couple of Smart document cameras, the 330 series. They will output an image from the camera absolutely fine to the projectors, but when you try to switch to outputting an image from a connected laptop it comes up with no signal. Sometimes it will give the message "Not supported, H: 48.30 kHz, V: 59.93Hz"; other times it has blackscreened or flickered. Weirdly, it seems to blackscreen if you put the laptop into "Lock".

I'm presuming it must be the VGA input on the visualiser, as I've done a direct patch from the laptop into the projector which works absolutely fine. Does anyone know a workaround for this, or am I looking at replacements?