Epson 4990 transparency glitches

[Mike]

Anybody ever seen a problem where the Epson 4990 transparency unit goes
flaky? This keeps happening, and usually a power-cycle will solve the
problem. But now the scanner appears stuck. Here is what it gives me
in transparency mode with the 4x5 carrier and a 4x5 transparency loaded:

http://www.cs.wisc.edu/~mikem/test_tranny.jpg

Reflective scanning works fine. Same thing happens with Silverfast,
EpsonScan, and Vuescan.

My first machine did the same thing and I returned it. It only happened
to my second machine occasionally so I figured it was a software glitch.
But now I am beyond the 30-day return period.

 

[-]

Are you sure you have the holder and its calibration notch is positioned
correctly? If it isn't, you get images with marks like these. Also, have
you made sure that the glass area that sits under the calibration notch is
absolutely spotless?

Doug

 

[Mike]

Are you sure you have the holder and its calibration notch is positioned
correctly? If it isn't, you get images with marks like these. Also, have
you made sure that the glass area that sits under the calibration notch is
absolutely spotless?

Thank you. You are better than Epson's technical support which did not
suggest that and told me to send it in for repair. Nor did the
Troubleshooting guide.

 

[Sarah Brown]

Anybody ever seen a problem where the Epson 4990 transparency unit goes
flaky? This keeps happening, and usually a power-cycle will solve the
problem. But now the scanner appears stuck. Here is what it gives me
in transparency mode with the 4x5 carrier and a 4x5 transparency loaded:

http://www.cs.wisc.edu/~mikem/test_tranny.jpg

I've seen this happen with my 4870 on occasion. The solution is to give the
scanner glass, the lid and the rear of the transparency adaptor itself very
thorough cleans. It seems that the problem is caused by something (dust,
fibres?) getting in the way of the scanner doing its calibration.