HP ScanJet 5100C Scan output has too much green and lines across

I have had this scanner for a number of years. It has always worked very well even when installed on Windows XP SP3.

I use it quite infrequently but it has done the job. Recently when I tried to scan in a document it came out very strange. There were horizontal lines across it and there seemed to be too much green in the output. If I can work out how, I will attach an example scan that should be completely blank (nothing on scanner glass).

Is there anything that can be done to correct this?

Thanks very much