Bizhub C451 Fuser problems

[Dave10]

Is anyone else having fuser issues with this model? We are having MUCH higher failure rates with the 451 than the 353 etc. Noise, rollers getting twisted and gouged, error codes. Has anyone found a way to rebuild these fusers? Say, aftermarket rebuild kits, maybe? They are so expensive, re-using them would be nice, but they are very unreliable. Any ideas?

[Tonerjockey.com]

These units have a very high failure rate and to my knowledge there is no kit or process to rebuild them. As an authorized dealer I can take advantage of the warranty process. If you are a dealer as well, then you need to be doing that. If not, I'm not sure what you can do. Konica Minolta has a 3 year warranty all of the consumables on most of their color machines manufactured after Jan of 2009.

[spock]

They are very unreliable items always have been, there is no fix for the rollers delaminating other than the machine might be unsuitable for the workload it's doing...

We are using our own modification kits on the fusing units now to fix the majority of noise issues though and issues with the brush roller which involves replacing bushings with higher quality items and modifying a couple of other areas in the fuser. Good results so far...

[Mr Spock]

I have not had any premature failures except for noise. Km has come out with 3 bulletins regarding noise. The 2 most effective ones are regarding the drive shaft needing spacers between e-clips and bearings, And the new belt drive mod. This converts the 3 drive gears to 2 pulleys and a belt.

[Tonerjockey.com]

Wow! Mr. Spock, you have had NO premature failures? Out of about 40 machines, I've had maybe 5 that didn't fail prematurely and many that have had the replacement fail prematurely. That is amazing. There was an initial bulletin that recommended lubricating parts in the fuser and there are also noise problems with the fuser drive unit. There is an available kit to eliminate the drive noise.

[spock]

When it comes to noise none of the mod notices really work that well even the recommended grease is not rated for the fusing temps. Any place that those black bushings are fitted you see abnormal wear usually and shaft polishing, replacing them with uprated metal bushings and high temp grease fixes the prob and stops annoying noises. Temp codes can normally be fixed with firmware and rollers coming apart usually come down to environment or machine duty cycle.

[Tonerjockey.com]

I've had them fail, more often than not, in standard office environments. Climate controlled, letter size paper, average volume, office environments. Some have lasted 20k and some have gone as long as 250k. It's the rare bird that makes it to 300k. Although I have had a few go to 400k. But that is maybe 1%.

[spock]

do you find the machines are doing too little workload or too much?

[Stirton.M]

I've noted a mixed bag with regard to failures.

Some fail with next to no use while others fail close to end of life. I had not thought of it up to this point, but I think there is a new article install date listed, though I could be wrong and simply thinking of the C65xx series that has this.

It would be interesting to know because the machine does roll the unit even when it is snoozing to keep it at a baseline temp for that quick warmup when needed. It could help in the long run to know roughly if and when a machine may fail, even one with low usage.

Nowhere near as robust as the older generations and not as reliable as a C353, though truth be told, too many of those I have seen fail miserably and I find myself cleaning out bits of red rubber from all around that section including second transfer.

Cool concept that induction heating, I like the fast heat up time, shitty manufacture of the unit unfortunately.

[suomi]

Fusing unit change soon..fusing noise C550-C552.jpg
If you want fix it now>>Fusing unit driving belt kit A00JR92900

[emujo]

Ditto on early replacement due to noise (squeek), but of all the C650/C652 series I have in place (50-60 is my guess), most make it to end of life. The only one I had to replace early was due to a wrinkle in the fuser belt. This was in a print shop and the MFP ran most of the day. Also, I see the belt kit part# as A0P0R90100, but it may be 2 #s for each family. EMujo

[Dave10]

Thanks for the comments. My problem is, we are an NEC dealer and we sell the KM machines, but under the NEC brand, and NEC has not bothered to keep us up on this info. Getting bulletins, etc. is like pulling teeth, and the warranties are the worst we've ever had on any of our products. We're going back to Kyocera. At least they stand by their products a little better.

[Tonerjockey.com]

do you find the machines are doing too little workload or too much?

I have noticed that in some cases time just ran out. In other words, the fuser is going to be able to withstand the heating for a certain amount of hours before it fails. So if that amount of time translates to one year, then if the customer does 300K in one year then their fusers will TEND to make their expected life. If the customer does 20K in a year, then that fuser will only make 20K. Although this isn't a hard and fast rule. I've put fusers in machines that are high usage and they still will fail far short of their expected life span.

I've tried combating this by lowering sleep times so that the machine stops heating sooner and more often, but inevitably the customer complains they are waiting too long for the first copy. I know...too long? But they are the customer.

So volume doesn't seem ti matter as much as time. It's my belief that given enough time, every fuser will fail.

[abscopiers]

We are also an NEC dealer, and unfortunately you were right about the lack of quality support. We have just began to sell the C451 style series, and are starting to have second thoughts about the quality of these machines. As mentioned, the C353 has been great, so we thought that the C451 would be as good. With only a few placed so far, we have had way more issues then the C353s. Mainly in the fuser (noise) and IU issues (ie. dumping developer). When we recently contacted NEC about the fuser noise, we were told to replace the fuser. Great advise, I wish we would have thought of that. It would have been nice to hear about theses fuser mods from NEC instead of on the internet. That is really agrevating. We have been trying to come up with some ideas of ways to fix the squeak. We will try some of the mods listed here and see what we come up with. I to think that we will sell the Kyocera machines in this segment until I feel more comfortable with the C451 type series. NEC did recently announce the 3 year warranty, maybe that will help, but still a pain.

[Stirton.M]

It is unfortunate that you have poor support from KM in your company. One of the many pitfalls of working for a dealer I suppose. Bookmark this site, you can often get support from the rest of the community here on issues like this one. There are many of us who ARE KM techs, we can answer most of your questions on issues related to the KM brand.

That said, you can order the new fuser unit complete with modification using the part number A00J R721 33 . The last two digits represent the newer type, so be sure to clarify that with your supply chain, though if your main supply has a bunch of the older type and will not bring in the newer ones for obvious reasons, the modification kit mentioned above will help you out for the time being. Alternatively, disassemble the drive gear section of the unit and clean and lubricate the gears and shaft with high temperature grease. There is a bulletin that discourages this, but our attitude up to now is that we simply do not care, grease works for the short term on those machines having this problem, usually to the end of the life span of the unit.

As for your problem with toner dumping, this is a known problem.

The lock levers that hold the unit in are insufficient in holding the unit in place. It drifts slightly forward and the unit will lose bias contact in the rear. When that happens, excessive charge difference pulls the developer out, leaving a lovely mess.

There are two methods to fix this. One is to put in a lock plate modification. I am not a fan of this method, as some customers replace their own. It involves the need for a screwdriver to remove the plate and then replace the unit and reinstall the plate.

I prefer the other method. In tray one, there is a cover over a cleaning wand for the laser glass. In that same spot, are replacement pads. Take one of the pads, cut it up into little squares and stick these onto the existing pads seen on the lock levers. I double up the thickness on the black one, the colours I just use a single layer. Seems to work well.