We have several RM branded Interactive whiteboards throughout the school - these are basically GTO-Calcomp devices rebranded. These boards are driven by Interwrite software, and we are using version 6.02.003. Most of the devices with shich we are having a problem are mains electricity powered, although one has had the control board replaced and is now USB powered.
The issue we are having is that, if the PC is connected to the School LAN, it is impossible to draw a complete line more than a few centimetres without breaks appearing in it. Hence, it is not possible to write on the board; teachers and pupils cannot drag and drop items, because the pen stops working momentarily, and stops dragging the item; in general, they are pretty useless except as a means of projecting a video. This happens whether or not the cabling is connected to a switch at the remote end; the mere connection of a patch cable to the wall port is sufficient to disrupt the board.
Once the PC is disconnected from the LAN cabling, the boards are fine.
So far, we have tested the mains supply for interference; we have replaced the board, the control board on one device, the patch cable, the USB cable to the board, the LAN switch, and all the PC's. We have run a new cable from the PC to the switch, and run a shielded cable from the PC to the switch. The fault is only present in one part of the school (which seems to me to rule out any effect from the server), and is particularly noticeable on three devices - all of which are powered from the same electricity distribution board, which they share with the school CCTV system.
The CCTV system also started displaying a fault at the same time, in that there is some form of interference on the display, which our service provider is unable to explain.
The LAN cabling through the roof void is clipped to the roof trusses so that it runs adjacent to the CCTV cabling. There is one board in this section of the school that does not have this problem; it was cabled at a later date, and the cable follows a different route back to the switch.
I have now exhausted all my ideas, and those fo a few other people (like the RM support function!). Has anybody encountered this problem elsewhere?
TT-W