Ricoh 7200 Image Quality Issues

MPNB

Member
Hello

I have been having some issues with my Ricoh 7200 that Ricoh hasn't been able to resolve so I am wondering if anyone may have some experience or insights.

My 7200 has less than 500,000 impressions and since the beginning of 2024 I have had techs in every few days to address the following issues to no resolution, they have replaced parts, sensors, drums, charge wires, developer and many other things:

- Fireworks / Chicken feet / Arcing on the last 2" of the tail of the sheet on the front side (pic attached). Techs said it was from a mylar plate holding static, they removed it and it seemed better but now I get color variation bands at the last 2". On the last call 3/7/24 the tech put a new mylar in and the fireworks are back.

- Color variation: the color changes within a run sheet to sheet and across the sheet - operator side has slightly different color than machine side and every few sheets overall color changes

- Front and back registration: on stock over 80# cover the back side of the tail edge skews in the corner by up to 1/8" - overall registration seems to bounce within the run as well

For color I now calibrate each stock I run daily per the techs, doesn't help the above.

All my stocks were calibrated for registration in the paper catalog and I make small adjustments in the Fiery when I notice registration is off but it's like chasing my tail because it doesn't hold throughout the run.

Any insights would be great.

Thank you
 

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have you swapped fusers?

New to Ricoh, only had our machines a couple months...but my Ricoh techs warned me about how running the same size stock in a fuser all the time will create lines that lead to the color variation you describe.

no idea about the chickenfeet issue though
 
We have a couple spare fusers and the fuser has been changed and rebuilt a couple times for other reasons. Running smaller width sheets and then running a larger width sheet afterwards does produce lines from the belt (look like lines of gloss at where the smaller sheet would line up to the larger sheet), but the belt scratch smoothing application does remedy that most of the time and we primarily only run on 12 x 18 or 13 x 19 sheets. Our issues all seem to be at the tail of 18/19" sheets.
 
In the photo - this is typically caused by buildup in the paper dust catch area (in the paper path just before the 2nd btr). There are two screws to remove this black cover, then vacuum it out as needed (I probably do this every couple of weeks if I’m running “hairy” paper).


As for color variations - I RARELY calibrate mine, and I only run a few base profiles (gloss, matte, and uncoated). Normally like monthly maybe, I don’t see big variations in runs. Most likely you have one or more bad PCU, charge rollers, or PCU cleaner. Run color separations to attempt to isolate issues to a color.

For registration, I use the “high quality” mode enabled under advanced settings, this is 35 sheets instead of 31. Also though check your paper, if the sheets themselves vary in size it is best to back trim the stock before printing to get it even. I do this on a couple stocks. Clean the alignment sensor before running alignments.
 
thanks

Tried the paper dust solutions with the techs previously, didnt help. PCUs. charge rollers etc have been replaced multiple times. All our registrations in the paper catalog were done on high quality. Interestingly when doing the auto registration calibration we sometimes have to do it several times to get it to register. Even after that the corner skews on the backside throughout runs. We’ve checked papers for squareness.

While we can get everything adjusted to look good, it just doesn’t hold
 
The registration issue is due do thicker papers hitting in the nip of the fuser rollers. In Advanced user settings you can slow the speed down and that may help. Also in the PTR area there is a registration stop or gate (similar to a stop fingers on offset press). The sheet hits this to register the lead edge before image transfer from the image transfer belt (ITB). The gate can be adjusted to correct skew, also, the bushing on the shaft of this gate can wear out allowing the gate to "bounce" on the operator side which can contribute to random mis-registered sheets.

As far as the " Fireworks / Chicken feet / Arcing" this sounds like erratic voltage discharge. Have the tech check the voltage the boards supply for each color and also on the ITB unit. Could be a bad contact point as well (i.e. building up resistance and then discharging) and there are lots of contact points that conduct voltage in these digital machines.
 
Those chicken/crow's feet could be caused by a bad oppose or bias roller in the ITB assy. Also, I found that (with Ricoh's) the humidity needs to be around 30% or higher or you'll have quality issues.
 

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