what do you do when you see lines or stripes in my images
Vertical and horizontal lines have very different causes.
Vertical lines means in the same direction of the carriage travel, down the page on a flatbed, or down the long dimension in a 35 mm film scanner. Horizontal lines means across the width of the flatbed, or across the narrow dimension in a 35 mm film scanner. Horizontal is parallel with the scanner lamp, and at right angles to direction of motion.
Vertical lines are due to certain CCD cells not responding properly, and that "bad spot" is moved down the page by the carriage motor, making streaks. The problem can be due to dust inside the scanner, on the CCD or mirrors, blocking light from reaching the CCD, and these tend to be dark lines (perhaps dark in only one of the RGB channels) and relatively few in number.
The vertical line problem can be a dirty calibration strip, due to allowing liquid to run under the glass edges. Scanners have a white calibration strip under the cover, just past the top edge of the glass, where the carriage is parked. They self calibrate on the light from that white strip. If this strip becomes dirty or discolored or damaged, the sensor cells in that spot receive the wrong calibration, which makes vertical sreaks down the page. The intensity of bad colors is probably affected by the image data (variable in some degree, probably not a constant). Don't let cleaning liquid seep under the edge of the glass. Put the liquid on the cloth, and then the cloth on the glass.
And the vertical line problem can be defective sensor electronics in the scanner, and these lines often appear as red, green or blue lines (stuck on), and sometimes in great numbers or width or patterns. Bad colors are probably a constant, not affected by image data. However, a deposited film on the mirrors can be wide and colorful too. Vertical lines tend to always be at the same place on the width of the scanner bed, being caused by specific CCD cells.
The vertical problem has also been reported as due to installation problems for parallel port models too, but in that case, the scanner never worked better, and the entire area of the scan is likely really terrible.
Horizontal lines are an event in time. Rainbow colored lines might be due to a flickering lamp. Or the scanner has an internal high frequency power supply for the lamp, and it might cause such a problem. A faulty or incorrect or insufficient power cube may be the problem. A long extension cord (AC power) can be a problem, try it plugged directly into the wall. Is the problem everywhere, or random locations, or always in one place in the carriage travel? It could be irregular movement of the carriage due to loose belts or sticky guide rods or other mechanical interference can cause "glitches". You might notice the lamp flickering, or watching the carriage carefully while it moves might show some type of binding. Horizontal lines due to lamp problems are random, showing at whatever location of the carriage at that point in time, but a sticky carriage would probably always be seen at the same location. Effects of an insufficient power cube is probably seen all over the image.
Anyway, you have to think about what you see, there is more there than just "lines". In any event, lines are not caused by your scanning procedure, and calling your scanner's Customer Support service seems a good plan.
Horizontal lines in your printed images are likely due to clogged inkjet nozzles. Your printer probably provides a utility to print a test pattern to check for clogged nozzles. If you cannot see the lines in the image on the video screen, the lines are probably caused by the printer. If you can see the lines in the image on the video screen, it is NOT due to the printer. The same idea with color casts, if the video screen image shows the color cast too, then it's not the printer. But if only the printed result is red, then you're probably out of Cyan ink on the printer.
