Savin SLP38 or Ricoh AP3850 Black Dev

[bob6313]

I have a Savin SLP38 the orginal problem was the black constantly was asking for toner even after replacing the bottle and then after a couple of copies it would ask for toner. Found the toner pump not working correctly and replaced it. Now while testing the machine the black was coming out almost completly blank looked like a very lite shadow. While diag the problem found that the black developer was not turning, switch the drive clutches between the black and yellow, where as the yellow, cyan and magenta are working with no problems. Still have the same problem with the black developer not turning while trying to make a b/w copy but if I make a full color copy the black dev turns and I get all four colors. The main motor is working a-ok. Even if I try to print the counter sheet the image is almost not there, that elimates the optics. I also replaced the black developer and pcu, still same problem. Checked all connectors and reseated them no help. Any ideas would be grateful and thanks

[Cipher]

Hmmm sounds like you have covered most things that I would of done to be honest.

But if you have definely confirmed the black dev unit is not turning during B&W printing then the problem is somewhat isolated.
As the black dev unit is driven by it's own motor which also drives the fuser and paper exit rollers.
So if there is no problem with the paper exit transport that rules out the motor.

So I think I would next try to confirm drive was actual getting to black dev clutch via the chain of gears.
Then I would confirm the correct 24 volts was getting to the clutch using a multi-meter and the machines output test.

Good luck.

[Scott_Lewis]

Have you tried doing a test print from SP5997 using black and single color and solid? If this works ok, then you probably have some f/w or nvram problem.?.?

[blackcat4866]

Are you sure that the black developer is turning when doing full color, or more likely, you're seeing process black (black composed of C, Y and M, but no BK) I suspect that if this is indeed the case you have a wiring problem to the black developing clutch (you say that you swapped out the clutch with yellow), probably in the harness or the board driving the clutch.

I would start by putting my meter on the clutch wiring to determine is the clutch is getting a signal to come on. If no, keep following it back to its source. If you get all the way back to the board, you must have a board problem.

On the other hand, if you are getting an On signal, and the clutch is coming on, it could be drive gears, or developer bias loss.

I think it is very unlikely that the black dev clutch is coming on in full color mode, but not black/white. If that is the case though, the only possible cause is a board problem.

[imaginemoko]

Sir try to replace the board where the dev and drum of black pcu are connected. after verifying that it has no siganl upon output check from sp mode.