Sharp MX-6201 poor yellow

[Mr. Fix It]

Hi!

I am working on a MX6201 with a Fiery Rip. When I print 64-1 with only yellow the colour is uneven. The fault is best seen when printing light yellow and green colors.
I have replaced the developer and installed a new yellow DV tank. The drums were change for a month or two ago.
I also cleaned the transfer rollers in the belt. I cant see anything wrong with the transfer roller.
Think that I want to change the belt and the transfer roller kit. But, I've heard from another tech that he had tried to open the laser and adjust the mirrors.
Any thoughts about the laser unit? I guess it could take from 15 mins to a whole day if you 'get lost'?

[bdcrandall13]

Hi!

I am working on a MX6201 with a Fiery Rip. When I print 64-1 with only yellow the colour is uneven. The fault is best seen when printing light yellow and green colors.
I have replaced the developer and installed a new yellow DV tank. The drums were change for a month or two ago.
I also cleaned the transfer rollers in the belt. I cant see anything wrong with the transfer roller.
Think that I want to change the belt and the transfer roller kit. But, I've heard from another tech that he had tried to open the laser and adjust the mirrors.
Any thoughts about the laser unit? I guess it could take from 15 mins to a whole day if you 'get lost'?

Can you notice the defect when copying as well? My guess is yes, but you never know. I would definitely check the transfer unit. Before doing anything with the laser run a half page test. Run a 64-1 with all yellow or a yellow "sky shot" and stop the pagew while the yellow is still on the transfer belt before the paper passes between the primary and secondary belt. If you have a good fill on the Drum, the problem isn't with your laser. If you don't have a good fill on the transfer belt but you do on the drum you've got a problem with the transfer belt, or the voltage supplied to the belt. I had a machine recently, (a 4100 i think,) that had a bad MC board with only yellow and black. Cyan and Magenta were fine. Try that and see what happens. I hope it gets you closer to a resolution.

[Mr. Fix It]

The defect is noticeable on copying as well. I will perform the half page test on my next visit. Just have to order in belt and transfer rollers, in case I need them.
I have tested without the shutter earlier, but I forgot to mention it. Thank you for your reply.

[blackcat4866]

The times I've had the exact same symptom, and done the usual inspections, it was caused by the follower roller (beside the yellow transfer roller within the transfer belt unit) not lowering down far enough to allow even tension of the belt across the yellow drum. This occurs a lot on the MX700 & MX701 primary transfer belt units when the separation cam inside the belt unit either gets contaminated or is unable to rotate freely enough. On severe cases, it can be caused by the separation clutches (forward or reverse) on the K drum drive unit/belt
As the yellow shutter unit has been removed & the dev unit replaced, it can't be those. =^..^=