Epson V750 failure?

[jolast]

Hello,

I'm using Epson Perfection V750 Pro to scan old photos. I'm scanning them with a small margin (1 mm) around them, so they are shown in full on the scan. I'm using a resolution of 800 dpi.

Regularly (in one scan out of four or five) something odd happens. I select on my screen very precisely the area that has to be scanned (with the small margin around the photos), but when I hit the 'Scan'-button, you can hear very distinctively that the scanner makes a small 'hesitation' just before the scan begins. The light of the scanner already has moved to the place where the upper border of the scan area is, but immediately before the scanning itself starts, there is a hesitation (the movement of the light slows down or breaks down shortly).
After scanning, the scan does not correspond with the selected scan area. On the finished scan, the selected area has slightly moved downwards, so I have on top a broader black margin and at the bottom nearly no black margin at all.
This is very annoying, as I have to make multiple scans again - it's time consuming and an expensive scanner as Epson V750 should do this right...

First I thought there was a problem with the moving part of the scanner, but this seems not to be the issue. The 'shifting' only occurs with high resolutions (as for instance 800 dpi). With a resolution of 300 dpi the problem does never occur.

So what can be the cause of the problem? It seems to be a memory problem? It can't be my computer, as I'm working with Windows 7, a processor of 3 GHz and a RAM memory of 4 GB.

Does anyone have the same problem and is there a solution?

Best regards,

Johan

[Uri A]

Have you tried 700 or 900 or 1200 dpi? Maybe it's just one of those "in between" numbers that's causing a glitch.

[jolast]

Hello,

I experimented as follows:

1) 16 scans on 1200 dpi. No problem detected.

2) 13 scans on 800 dpi. No problem detected.

3) 18 scans on 800 dpi, but now with small adjustments of the selected area between the scans. Finally the problem reoccurred.

4) 12 scans on 1200 dpi, also with small adjustments of the selection between the scans. No problem detected.

5) 7 scans on 720 dpi, also with small adjustments of the selection between the scans. At the end, the problem occurred again.

So it seems to have an influence if I adjust the area that has to be scanned.
Is there any explanation for this?
And can the problem be solved?

A side effect of the problem (I forgot to mention yesterday) is that the scanner light sometimes switches off between two scans. If one scan has been completed and the light has moved to its starting position, it switches off. It seems as if it is 'resetting' itself. Before a new scan, the light makes a small movement forward and back, just as it does when I'm switching the scanner on.
Tonight, I had this switching off problem with 800 dpi and 720 dpi, but not with 1200 dpi. With 300 dpi, the switching off occurs neither.

Any suggestions?

Best regards,

Johan