Mpc 2503 - light cyano halos effect around the text despite dev&pcu already replaced

[luca72]

hello everyone, monday or tuesday, i have to go and see a mpc2503 from a customer who usually follows my colleague, we checked in our management system and both the cyano developer unit and the cyano pcu are replaced a month ago at bk=39k cl=167k, now the problem has reappeared, (but I'm not sure if it was already fixed).
I have unlimited spare parts available in the warehouse, and several mpc2003 and 2503 units here with us, I am attaching the defect that the customer sent me via email, what do you think it is?
its already happend to me the same defect with black color on mpc2051 some year ago, but i dont remeber what i do that time.

p.s. enlarge the attachment well to see the defect, where there is the cyano component, there is the halo

[tonerhead]

For troubleshooting, try swapping cyan and magenta drums to see if the problem moves with the drums.

[luca72]

For troubleshooting, try swapping cyan and magenta drums to see if the problem moves with the drums.

thanks, the first thing I will do is insert a complete cyano pcdu (used), recovered here in the laboratory to see what happens, my colleague changed for the same problem cyano dev unit and pcu new from the box a month ago

among other things, today the customer wrote us back, pointing out that now when he prints blue, it comes out pink

[slimslob]

It might be drum charge or developer bias.

[copier tech]

hello everyone, monday or tuesday, i have to go and see a mpc2503 from a customer who usually follows my colleague, we checked in our management system and both the cyano developer unit and the cyano pcu are replaced a month ago at bk=39k cl=167k, now the problem has reappeared, (but I'm not sure if it was already fixed).
I have unlimited spare parts available in the warehouse, and several mpc2003 and 2503 units here with us, I am attaching the defect that the customer sent me via email, what do you think it is?
its already happend to me the same defect with black color on mpc2051 some year ago, but i dont remeber what i do that time.

p.s. enlarge the attachment well to see the defect, where there is the cyano component, there is the halo

Can't really tell from that print example.

Are they using genuine toner?

Take a good cyan PCDU with you when you go back.

[tonerhead]

thanks, the first thing I will do is insert a complete cyano pcdu (used), recovered here in the laboratory to see what happens, my colleague changed for the same problem cyano dev unit and pcu new from the box a month ago

among other things, today the customer wrote us back, pointing out that now when he prints blue, it comes out pink

Sounds like developer issue. Suspect drum is pulling developer maybe because of bias issue on developer unit. I would replace entire pcdu assembly and make sure of developer bias. For grins, rear cover on pcdu is on and copper contacts and contacting what they are supposed to, right. I venture to guess if you split the drum/dev assys, you will find it is missing developer on the mag roll.