M552 is missing magenta and yellow colors

[ChrisPiepen]

Hi,

our Printer (~24.000 pages) is missing the yellow and magenta colors while printing.Black and cyan are working fine.

Things tried so far:

- faulty cardridges replaced (yellow 90%, magenta 30%, cyan 10%, black 90%)

- cleaned everything

- tried to google the issue

- reset to factory standard

- drivers updated

- firmware updated

- switched from Ethernet to USB

- switched magenta and cyan cardridges in printer (I had to switch the little chips to fool the printer ;-). The magenta cardrige in the cyan slot was working. The cyan cardridge in the magenta slot wasn't 😕

What else can I do to get it running again?

[Valsimot]

Check the grounding spring on M and Y toner cartridges just above each toner cartridge, if you are lucky the contact spring might be damaged or bent. 

The next step would be replacing the transfer belt and the worst case defective laser unit. The M and Y share the same laser.

[ChrisPiepen]

Hi, thanks for the response.

The grounding pins are looking good and touch firmly on all cardridges when closing the door.

I had the transfer beld removed while looking for the error and didn' find anything unusual.

Can I check/replace the laser unit by myself? Maybe it's just a loose cable.