I saw this once
I saw this once
Of all the 3050s I've worked on, I think I saw this only one time.
I have looked for my 3050 service manual, but must have misplaced it!
The photo filter unit is a set of 3 or 4 ND filters on a disk. The disk spins by a motor.
Problems with this are very rare.
Luckily the place I saw the problem with had a spare parts machine.
There are also some parameters that belong to each different disk, but this might not be too important/critical.
During bootup, the motor should drive the disk to a home position, and from there it rotates to bring up the ND filter needed. This mechanism is in the optics cabinet and is the first thing after the laser itself.
It's possible a fuse to the motor has blown. I don't have my manual, but the fuses are on the main control (CONT) board (which sits in front of the optics cavity, on a hinged slanted panel under the film load cover.)
If you look at the top of the board, you will see the fuses. They are unusual, not glass, but instead are green colored, and I think the board is labeled FU1, FU2, etc.
Not sure which one is for the Filter motor, but you can check them all. The leads on them just push into sockets in the board. Maybe there are 6 to 8 fuses there. The only one that you usually had to change was for the cutter motor.
If this fixed it, and the motor was running roughly, but somehow you got output to work, and always use the same settings (2400, etc) you might want to leave it on all the time, because I think it won't have to move ever, except at bootup.
I'll keep my eyes out for a spare parts machine, if the fuse doesn't solve it. Or, you might be able to order it from screen. No idea of the price, but sometimes their parts are surprisingly reasonable.
