[CQ] Missing yellow color mpc2500

[kayjaig]

i have seen few machine missing part of the yellow color ( See photo of test page). force yellow toner can not make any better. Someone please help. thanks.

[wfinn]

transfer belt. This is actually common. The roller under the transfer belt will either fall off or the holder will break off under the affected color. sometimes you can take the belt unit apart and fix it but with as cheaply made as they are its usually easier to replace. I have only been able to fix one of three. Two of them came broken from the factory brand new in box and one happened over time. Does the exact thing you show on the picture.

[pro.b.unal]

laser unit should be fixed on the metal cover

[teebee1234]

Did you or anyone else recently replace the developer unit or work on it? Besides wfinn's mention of the transfer roller, another common problem with the same symptom is the rear brass bearing wasn't put in or fell out where the mag roll shaft goes through the rear pcu frame. That will cause the light/blank area due to the rear end of the developer not against the pcu (unless that blank area is at the front edge, then I would also suspect the transfer).

[Silvertoast]

as stated above its the transfer unit, the yellow roller in itb is failing to raise up on that side

[Zeldaman]

Hi there!
Very important on MPC 2500: installing new firmware, there was a bug and therefore the shutters of the printerhead opend not completly.
Greetings...

[Gift]

Stop the machine during printing a full yellow page / large format and see if the toner image looks ok on the drum - in this case it would have nothing to do with the transfer unit. The laser shutter issue may be a reason as well as other possible problems within the PCU (improper contact of the charge roller...).

[jonw]

teebee 1234 spot on

[Ramón]

[teebee1234]

Lack of charge will result in a solid yellow band, not blank/light area.

[drug-z]

I would be lookin at transfer belt.

[Ramón]

Teebee1234: Your point of view that's fine. I still think the problem is in the PCU Y. The back of the Unit Charge is removed from the site and the tabs that engage the block are not well placed PCU thus no load on that part of the drum and this phenomenon appears. This usually occurs when the PCU is caught by the bottom and exit the site Charge Unit

[teebee1234]

Teebee1234: Your point of view that's fine. I still think the problem is in the PCU Y. The back of the Unit Charge is removed from the site and the tabs that engage the block are not well placed PCU thus no load on that part of the drum and this phenomenon appears. This usually occurs when the PCU is caught by the bottom and exit the site Charge Unit

It's really not a point of view but a fact. If you're saying the charge roller is not flush against the pcu on the end then the only outcome would be a solid toner band, not a blank area. Lack of charge using the Ricoh "write to black" process will result in toner being attracted to that higher (more positive) potential. The toner has a high negative charge and with no charge on the drum (or more positive as it relates to the toner charge) then that is where the toner will attract to.

[jonw]

The problem is not charge. if you remove charge you get solid toner.i'm afraid teebee is correct.Just remove charge roller and take a copy.

[Smee]

Im sure ive seen this before and im sure I took out the laser shutter. It was only the yellow that was affected.