Minolta Di-350, orientation change at random.

[Hansoon]

[mtech]

Sounds like a width sensor issue. The only issue I have seen with this is bending of the white guide over the slit glass. That just causes a ripple on the edge of the copy.
Good luck.

[deep]

Clean and re-calibrate the Original Size Sensors with Function Mode F7-1.

[fixthecopier]

This may not be related but one of the biggest problems I had with the Di250/350 machines was the top tray size detect. When the operator would shut the top tray and the machine would show what it thought was in there and ask the operator to select enter if it is correct. Of course when the tray showed the wrong paper size or direction the customer still will select enter, then the machine reacts based on what they told it was in there. Does your problem occure from the other trays? Did you check to see that the paper sizes match what the machine thinks is in them? I bet I did over 200 work orders where that was the problem.