This machine came up with c-4000, i replace the laser unit machine fire up OK no problem until I started making the registration adjusments i noticed it's missing yellow print and copy checked and reseated all connectors, reloaded firmaware problem remains, any sugestions? thanks M.L.

Adj. the color reg. maybe it is so far off that it is not printing. I have seen this on a 5030.

Just an update, i had a bad laser out the box, replaced laser second time, did all my adjustments machine up raning again. thanks for your imput. ML.