Random Color blotches IRC6800

[BobComeau]

I have a new issue with my IRC6800 that may have been there before and not noticed or I've caused it with my recent activities. Small patches of pure color, just one at a time but all three at one time or another, and appear at random points on the page. The are a bit hard to describe but remarkably similar when they appear. They start as small circle about 1/16 " across and they appear to be repeated in a line for about 1/4". The length varies a little but not much.

I've cleaned what I can get to without removing the color dev units and rotary turrent including the drum cleaning unit, removing the drum itself, the ITB unit. It did help some, they seem to be less frequent now.

I'm reluctant to take out the developer without some new starter on hand to restart them. I find it odd that it is not just one color, but never black. Occurs even on black only pages. It is not enough to make the machine unusable, about 1 in 30 pages have it now.

Any suggestions and thoughts welcome.

Thanks,
Bob

[Paul 75]

If the marks show all three colours together at the same time then your drum could be marked, hard to see when you take it out I have had to replace one but it took me a while to figure it out. But mine was happening all the time, other than that ITB blade and drum blades need o be replaced at 120k, when these fail it causes coloured marks. I would start with the blades first.

[CanonHPTech]

Do not rule out your Upper Fixing Roller having some type of damage, but I would recomend starting with your Transfer Belt and Primary Transfer Roller (inside the belt assembly, under belt) first. Inspect the Belt closley for possible adhesive from a label or other damage/substance. Also, if your Primary Transfer Roller collapes when you touch it gently, than it's time to swap it. Good luck.

[BobComeau]

Thanks,

That's one area I hadn't looked at that closely, great advice!

I'll have another look.

[WOMBAT]

IRC 6800

Dear Bob,
The Drum of the IRC 6800 is As (Amorphous Silicon) It was rated for 3 million copies. You can polish this drum with Jeweller rouge( A very fine abrasive paste) Don't use Brasso as it will stuff your drum.When the 6800 really gets dirty in the process unit it always leaves marks because the colour toner beads are encased in a wax which allows the copier not to use silicon oil. This wax gets onto the drum cleaner blade plus the ITB cleaner blade and causes smudging and offsetting. Also when you remove the ITB belt check to see if the Transfer 1 roller is grounded properly. There should be a contact that touches the Transfer 1 roller.Also check to see if the transfer belt is tensioned correctly.They have a habit of breaking the tensioners.

[BobComeau]

Thanks for info Wombat. Greatly appreciated!

I had been wondering what I could use to polish the drum. It only has about 880K on it, but all toners were still in the machine when it was shipped to me and I've been cleaning various parts ever since. The ITB looks pretty good but I'll be sure to check on the ground you mentioned.

Is there anything 'safe' to lay the drum down on when it's out? Seems I don't have enough hands to keep it on it's end and be able to do much else. A extra pair of hands came in handy the last time.

[555]

sounds like "doughnuts " caused by stray toner circulating inside machine magenta is usually the most common, typical of cannon collor copiers, try thourough cleaning .

[BobComeau]

Last night I did whay I would consider a thorough cleaning, including removing the drum, developers and toner cartridges, ITB, waste toner area on the right of the drum, several filters, emptied waste toner bottle (about 1/4 full). Cleaned all parts as they were going back in.

Discovered the entire process unit lifts out which made cleaning in and around it significantly easier. It was fairly light with all the stuff I'd taken off and out of it.

Getting the toners and dev units back in without making a mess proved somewhat challenging.

But it appears the effort (about 4 hours) was worth it, after a few initial pages with some black toner specs and still a couple color blotches, printing a 1700 page book appears to have sucked up whatever stray toner remained. Along the way there were a several pages that had areas with quite a bit of extra toner in a band about an inch wide, but that too cleared up.

Hopefully it will remain working well for a while now.

Thank you all for suggestions and advice.

Bye for now.

Bob