Can't scan after printer upgrade

Helpline Q&A Directory

I upgraded my printer from an Epson 440 to an Epson 760 unit, connecting it (through the scanner), uninstalling the 440 software and installing the 760 software. Now, when trying to scan, I receive an error message telling me the scanner is 'Not connected, please check cable'. Through a process of elimination I found that if I switched the printer off and tried another scan everything worked okay.

I tried uninstalling the software of both the printer and scanner. I then reinstalled the printer, followed by the scanner, but the problem still remains. I can use the scanner and printer separately, but if the printer is switched on I can't scan anything. Do you have any ideas please?

This is a common type of problem. The reason it occurs is that two devices can only share a printer port if they are both 'dumb' devices that only send or receive data when they are actually being used. Modern printers, however, are constantly in communication with their drivers, sending back status information about how much ink and paper is left and so on. This prevents anything else from using the port.

The idea of two devices sharing one port is a nasty kludge anyway. It's an attempt to get round the problem of a PC not having enough interface ports, without going to the expense and installation hassle of using a separate card. The USB port was designed to be the solution to this problem.

In this case, you are lucky that simply turning the printer off allows your scanner to work. Some people find that one device won't work while the other is attached at all. The only real cure is to buy and install an extra parallel port. This means that both your printer and scanner can have exclusive use of the connection.