Slow Scanners

I have problems with scanners where I work. They do heavy duty scanning as in number of documents to be scanned and not a resolution thing. After sometime, of about 6months the scanner becomes really slow. I have explored all avenues and have come to the realisation that it is a hardware problem. I believe there is a component in the scanner that acts as a timer and it gradually gets bad. No matter what I do, installing a brand new system and attaching same scanner to it, it scans slowly at almost the same speed, including when the DRAM is doubled. Can someone help me out with the hardware component?