How do we know when the fuser unit in our Canon IR3220 needs replacing? We were advised to keep one on hand, which we have, but nothing about when to change it. Lately, ink on large solids feels rough and sometimes flakes off. We normally run 12 x 18 Mohawk 100# dull coated text, two-sided, or the same in Xerox brand. We used these papers in the past without a problem, but recently we began having problems. The drums are still within their lifespan. Thank you.

First I'd take the fuser out (two screws, easy), release the pressure level, and rotate it by hand looking at the surface of the rollers to see how they look and if you spot any melting/hard spots or if they look smooth and good.

I have not run any 100# text weight on our machine, so I don't have an answer for you, but a few comments:

What weight setting have you set (register paper type on the machine itself for the drawer or stack bypass) -- are you running the 100# as normal, heavy1, or heavy2?

Running 85% 20# bond, and then 15% as a combination of 24# Accent Opaque, 28#/70# Hammermill, and 32#/80# Mohawk, we have gotten 90,000 - 95,000 11x17's out of each of our fusers on average (and pretty close to this, within +/- 5,000 11x17's) We run the machines hard with runs of 23,000-28,000 done in 2-3 days and then just a few thousand the rest of the month and idle (cooled down) for most days of the month; we haven't deviated enough from this to speculate how run length effects it yet. We've run both Canon OEM fusers and NWRS / IKON rebuilt fusers.

I run up to 32#/80# weight as standard/normal weight.

I did encounter one case where running 28#/70# hammermill in a quantity of 100 11x17 posters had the same symptoms you show - black toner flaked off while the color toner on the page which was in a lighter screened area held fine. But they all had to be discarded and run again as the black lines flaked off the page. I re-ran those as heavy1 when then worked ok (but wasn't sure if it was a one-time glitch with the machine, or a paper issue possibly.) and after that all was fine running the same weight paper as normal weight (with the same fixing unit... for some reason it was an isolated issue and has not happened again with 700,000 prints run on that machine with various fusers from then until now.)

We have only replaced fusers when the rubber roll actually melts - either we catch it when the paper is rippled and then when you look at the fuser heat roller you will see the rubber is melting under the clear plastic surface of the roll and rippling it, or if we don't catch it the machine will actually stop when it can no longer turn the melted fuser (sometimes within 50 sheets it will not only melt/deform under the clear sheet but will also have a chunk of rubber tear up so it is un-turnable.)

We did have one other case where we developed a "hard spot" as a visible line across the fuser which created an undesirable bad spot ("oddly" fused areas with slight toner displacement in the 11" direction of an 11x17 the circumfrence of the fuser apart). I'm not sure why this happened on that one fuser... one glitch I have noticed with the machine (but which other techs have not seen or do not think is a big deal) is that sometimes with no jobs in queue and shut off either through timer or by hitting the gray soft-power button off, the machine will for some reason keep the fuser hot. So I try and check to make sure the fuser has cooled down at the end of the day. A couple times I've run late, turned off the machine after the last job was run (and with none in the queue, no errors, etc.) and then found the fuser still hot 170-190 °C the next morning. Now in theory the machine keeps rotating the fuser anyway, but I suspect there may be a glitch condition that occurs rarely where the fuser stays hot but stops rotating causing a hard spot to burn in. But other techs have not seen this, so this is only my speculation. And I try my best to make sure the machine has cooled down at the end of the day by checking 30-60 minutes after I've turned it off (both of our two IRC3200 and IRC3220 rarely but sometimes otherwise keep the fuser hot, seemingly indefinitely, (though they both usually turn it off as scheduled - I've not had a fuser "burn a line in" in the 3220, only the 3200 and only once in the last 4 years.)

P.S. in theory I suppose going into service mode and running a NIP check would be in order to make sure the fuser is applying the correct and even pressure; I've not encountered a Canon fuser mis-set though in practice but my experience is only with one every 6 months or so, a pretty limited sample, and I don't think it would hurt to rule out anything you can rule out.

Thank you Jeff. I am going to pull the unit as you suggested and look at the rollers. We do not run single large quantities as you do, but a lot of jobs throughout the month, about 35K a month total. Most of that on 11 x 17 100# dull coated text or 100# dull cover. We avoid gloss text, it starts to blister on the 2nd side, or the toner will smear and the sheet is really hot. We have tried all settings with gloss.

We only run coated of any kind through the bypass, a slow, painful process.
Are you guys running coated from the regular trays?

Adhesion is never a problem for me from dying fusers. Mine always start wrinkling then jamming near end of life.

We run a wide variety of papers, laser 28, 32, coated 80, 100, cover 80 and even 100. She's even taken 12 point Kromekote.

I like Futura brand paper for coated, she NEVER blisters on that. Any Sterling or Utopia she just spits out with second degree burns.

Not to take this off topic, but have you achieved a decent look on gloss? With our 3200s the toner is so flat matte that it looks odd on gloss; we tried it a couple times when they were new but the results just didn't look good (matte toner on gloss sheet) so we gave it up.

It's not possible on the 3220 in my experience. The wax based toner only ever appears matte. The only way it works is on little or no coverage. The more you lay on, the less paper shows through. Even tints of colors are enough to flatten the shine.