Photo scanning problem
 

In the process of scanning a large batch of colour and B&W slides. The scanner is a Minolta Dimage Scan Dual IV and the TWAIN provider is Adobe Phoroshop Elements. The first 20 or so were fine, but, for no apparent reason subsequent scans have generated the white line as seen in the pic below. I have tried gentle air cleaning but no improvement. Any helpful tips. please ?
TIA

https://cimg1.ibsrv.net/gimg/pprune....f28fe69300.jpg
The pic is Kanchanaburi WGC memorial (Kwai river bridge)

It's a small rainbow of colours, almost as if something is refracting the light from the scanner at that point. I don't really have a clue but it could point to something that is on the scanning element itself or on the light source. As such, the scanner is not really usable, so perhaps a bit less gentle cleaning? Can't think of many other solutions. Is it always at the same location?

Looks like contamination or (oh no!) a scratch. If it lost a channel it would be a single color, such as cyan or yellow or magenta. If it lost all channels it would be black. An adaptation is to turn the slide 180 and scan it a second time and then use the second to correct the first - which is a lot of pain, but is doable.

If you search there is a web page explaining how to strip and clean that model of scanner.

In this case you could crop it without losing too much (though you may not agree)

https://cimg0.ibsrv.net/gimg/pprune....94593e0d4a.jpg

On my one at work, (different model) we need to clean the glass over the scanner head every now and then with isopropyl alcohol as that’s a classic symptom of what happens.

Thank you for that - the problem was (expensively) solved by buying the Vuescan Professional package. If I was a conspiracy theorist, I could easily be persuaded of 'possible interference', since the problems started when I downloaded their free (watermaked) version, while still using the PS Elements, Vuescan works very well and at £100 a licence, so it should !
I might have to do a little experimental loading on another machine, to see if the problem replicates :(

You can't go wrong with VueScan. It's a terrific program, and also continuously improved.