I have a scanner - Canon LiDE 20 , it worked for a month perfectly , but since yesterday, whatever i try to do it writes the following error message:
Release the lock switch, disconnect the USB cable and reconnect, then restart toolbox
Scanner driver will be closed
Unable to locate TWAIN source
Is there anything to do , except going to the distributor . Why that error appears, cause the lock switch is on released mode
iirc, this scanner is powered through the USB cable instead of an external power supply. Is that correct?
A number of months ago I had a client who suddenly developed a scanner problem on one of these (can't remember if it was a LiDE20 or 30 though). The exact error message escapes me, but it turned out to be that the scanner somehow ended up plugged into a standard USB cable instead of Canon's specific scanner cable (I think he was trying to use a longer cable). Using the correct cable ended up taking care of the problem. Beats me as to why.
Otherwise I'd probably give Canon a buzz for some help. Life will be easier if you do the usual troubleshooting nonsense first ... e.g. undo whatever changes you made since yesterday (if any); see if it works on a clean system; etc.
After muddling around for a few hours, I discovered it had nothing to do with the scanner at all! I stumbled on the solution by accident unplugging an external drive that was on the same USB hub as the scanner. Try unplugging any other USB devices and/or plugging the scanner into a different port.