Scanning Streak

I have the Epson 4990 flatbed and have used it quite a few years without incident.

Now, when scanning a neg I'm getting a black hairline streak in the scan, the full length of the bed. It is not their when scanning a document or photo or anything but a negative. It appears in the same place on all negative scans.

Any ideas on what may cause this, or how to fix it?

Thanks,

Bruce

It could be as simple as a small speck of dirt on the glass bed right under where the calibration gap in the holder sits when the holder is placed on the glass bed. That area has to be absolutely spotless or it will miscalibrate and cause an issue like you see. If it isn't that, then you need to see if dust has gotten down onto the sensor or mirror assembly. Put your scanner on its side (but not totally perpendicular) and run a few scans. If the line is still there but the line's location moves, then you have a dust issue and will need to disassemble your scanner to clean it.

Doug

Doug,
Thank you for your insight. I will begin trying to solve the problem using your thoughts. I'll post my outcome in a couple of days.
Thanks very much,

Bruce

I once was getting a thin, light red line across each of my 120 medium format chromes taken with my Mamiya RB67. I finally tracked it down and found stretched across the film back opening where the film is exposed was one of my lovely wife's long red hairs!