PRESS C1060 with errors

[blackcat4866]

C2456, C4521

The machine was recently PM'ed, C:509K, BW:26K
It's a bit early for the magenta developer but it's the only logical conclusion I could come to. All the toner sensors read between 29.7K and 30.0K, magenta marginally higher than the others. I swapped TCRS4 with TCRS2 and got the same results. The magenta developing motor runs along with the others.

I thoroughly cleaned the color registration sensors twice. Naturally there was a toner dustcloud to clean up, but none inside the sensor housings. The registration assembly is fitting tightly to the transfer belt frame.

I have gotten it to run for short periods of time, mostly just dumb luck. I got a Management List loaded with both codes, nothing else. If it matters, this enduser has printed exclusively BW for the last month.

Did I miss something obvious? =^..^=

[ysshin79]

C-2456 error indicates that there is a lot of toner inside the magenta developing unit.
Set the service mode test pattern 53 to 255 and lower the magenta toner density by printing more than 20 sheets.
It is processed when the value returns to normal after executing the toner density revert mode.
The C-4521 probably appears to be lit due to a magenta problem.

[ysshin79]

A few years ago I noticed that the C-2457 lighted on the two equipments and the cyan toner density was lowered and processed no more.
And I likewise lit the C-2457 behind the black-oriented output.

[ysshin79]

C2455/C2456/C2457/C2458 Toner density abnormality(High density) occur
(1) Symptom
C-CodC2455(Y)/C2456(M)/C2457(C)/C2458(K)（Toner high density abnormality） occur.
(2) Cause
 During long-run low coverage print, Toner charge is deteriorated due to lubricant attached to toner. Developer level became deteriorated due to Toner charge deterioration and Toner density sensor judges low after that Toner supplied.
 It rotates above, Toner density becomes high.
 After that, Toner high density occurs as Toner density sensor judges high, attached lubricant toner is consumed, Toner charge and Developer level becomes normal.



Extracted from bizhubPRESSC1070_Troubleshooting guidev2.0E.
How to deal with the problem after the firmware update to replace the problem, the toner band to increase the generation, but it does not need to update the firmware, it seems to be enough.
As I wrote above, lowering toner density from test pattern mode to halftone will not be costly.

[blackcat4866]

It took some experimenting to figure out the Test Patterns but it worked well to de-tone the magenta developer. I used test pattern #1 with magenta at gradation 128 (and CYK at 0). The thing not mentioned in the documentation is that Full Color mode must be selected in the Print Mode. It took 60 ledger sized prints to detone magenta 200 points from 30010 to 29810, and it stayed stable after that. The toner density revert mode only ran for a few seconds.

The C4521 remains a problem though. I took out the color registration two more times, though the first 4 times didn't help either. Everything has been cleaned multiple times. The color registration assy pulls up nice and tight to the transfer belt frame. I did notice a few ragged edges there the tape that covers the transfer belt edge strips came off, had peeled back 13mm or so. The rest of the transfer belt looks ok, tracking straight, and no major defects in it's surface. I've ordered up the front color registration sensor PS60. I don't see any particular calibration for it.

The test patterns look great. No problem with image fill whatsoever. If PS60 doesn't do the trick, primary transfer belt next. =^..^=

[blackcat4866]

One of our techs pointed me in the right direction:

Apparently it's not mentioned in any of the documentation, but any time that you clean or remove the color registration sensors, you absolutely must run the Color Registration Auto Adjustment. It takes about 2 minutes to run. All of the display values shifted (most to +0.000), and it resumed working immediately.

I had the front registration sensor on-hand, and did not need to use it. Thanks for the help! =^..^=

[blackcat4866]

I just came across this again. The circumstances were the same ... and a little different.

Unlike the other time, on this occasion I had just changed 4 drums, 4 developers, and 4 primary chargers a few days earlier. Like the other time, this enduser had ran 35,000 light fill black images ... no color at all ... in just a few days.

The way I'm reading this situation, the color developers just sit unagitated. The toner density sensor output reads fine by the time I get there (29650 to 29850 across the four colors). The manual speaks of errors caused by excessive drum lubricant immediately after the drum change. Then I went back to this thread and saw the bit about exit toner band.

The way I read it, the exit toner band is intended to lubricate the primary transfer blade when large numbers of low fill images are run. So far, this fits the situation. I think the tiny amount of toner usage from putting down that exit toner band will also allow the color developers to stir a little, and maybe feed off just enough toner to prevent the false high toner density errors.

The DIPSW settings were a little hard to understand. Maybe somebody can explain to me how this works. I set:
44-5 to 0
44-6 to 1 creates a 1.5% exit toner band above a certain internal temperature

49-6 to 0
49-7 to 1 creates a 3% exit toner band on K only images

59-6 to 1 enables exit toner band
59-7 to 1 retracts the 2nd transfer roller during the band passing to avoid contaminating the 2nd transfer roller

59-2 to 1
59-3 to 1 always create exit toner band

Do you think that some of those settings are redundant? I couldn't be sure. =^..^=