No black prints from Sharp Mx4501n

[Walks]

Ok, My Sharp MX4501n does not print black. A self test shows that the black is missing. I changed the black drum but this does not solve the problem. Any suggestions would be welcomed.

[ZOOTECH]

Ok, My Sharp MX4501n does not print black. A self test shows that the black is missing. I changed the black drum but this does not solve the problem. Any suggestions would be welcomed.

Check your PTB, and laser shutter for Blk to see if it's opening.

[Silvertoast]

possibly the roller for blk in the transfer unit isnt lifting

[Walks]

Check your PTB, and laser shutter for Blk to see if it's opening.

Thanks Zootech. The PTB has signs of Magenta toner but not black. How do I identify and check the LSU shutter for Black? I am not seeing the shutter on the service manual. There is however mention of the shutter solenoid.

[Walks]

possibly the roller for blk in the transfer unit isnt lifting

If this is so should I replace the PTB then or is there a way I can verify this? - i.e that the roller for black not lifting.

[ZOOTECH]

Thanks Zootech. The PTB has signs of Magenta toner but not black. How do I identify and check the LSU shutter for Black? I am not seeing the shutter on the service manual. There is however mention of the shutter solenoid.

Remove PTB, DRs, and DV units - the shutters are on the bottom of that area.

[ZOOTECH]

If this is so should I replace the PTB then or is there a way I can verify this? - i.e that the roller for black not lifting.

TC 6 (load test) should rotate between "free, Blk, and color".

[Walks]

TC 6 (load test) should rotate between "free, Blk, and color".

I believe you are referring to SIM 6-3. As soon as I run this I would let you know. I may not respond immediately as I would not be revisiting this unit until next week.

[Walks]

Remove PTB, DRs, and DV units - the shutters are on the bottom of that area.

Ok. I shall check the shutter. Apart from physical examination, is there a simulation I can run to check shutter operation?

[ZOOTECH]

Ok. I shall check the shutter. Apart from physical examination, is there a simulation I can run to check shutter operation?

With the units mentioned above removed, run TC 6-1 to initiate LSUSS. You should see the shutters open fully, if not, it's possible that the solenoid is dirty and not pulling the blk shutter open all the way or the spring on the shutter
is not allowing the shutter to open. You can remove that spring and see if that helps, or just switch the yellow and black shutters to see what happens.