C451 Eating up Yellow IU

[big jase]

hope someone can help, i have a c451 taking out the yellow iu after about 20% life the unit fails giving nearly blank copies from the yellow unit, i have checked connections to hv board all looks ok but fault still remains

[Kmdurrin]

Has it done this with more than one yellow IU?

[JSC]

Is the collection btl full of yellow dev?

[fishleg]

Great had exact same issue yesturday at a customer figured it was a faulty yellow IU that cured the problem then but was it a temp fix I wonder now ffs.

Touch wood no callback yet but am definately intrigued now as to what was going on my drum was almost at the end of its life when the yellow went almost blank except the outer most edges on the copy.

Will keep an eye open and see what happens...

[Stirton.M]

This series machine, you need to ensure ALL the dev units are in the machine properly. I have found on some occasions that if the dev units do not sit properly in their respective locations when you slide them in, dev bias is not assured and they will tend to void themselves of developer. A telltale indicator of this is if the dev unit springs out slightly on its own if the lock tab isn't locked after you push the dev unit in. If it doesn't spring out slightly, near as I can tell, this is normal. I think this is because of the drive coupling in the back not making a proper mating, which pushed the dev unit out slightly (against the lock tab) and the bias contact is poor as a result.

[Mr Spock]

3 iu units, 1 hv1 pwb, prcb, and the final fix was the transfer unit....... All by the direction of SSD. (Excpet the transfer belt they said it would not cause this.).
Took 3-4 weeks to empty the developer. after replacing the last iu and the transfer belt it has been 3 months.

[Stirton.M]

I agree with tech support, the belt should not have caused that. Was there some kind of physical damage to the first transfer roller on the IU in question Causing it to make physical contact, via the belt, to the drum? That would be the only thing that I can imagine would perhaps change the drum bias enough to literally pull the starter out.

[mtech]

How are these units being stored? They come in boxes that try to help improper storage. I had a customer have problems with image cartridges constantly and found they had been throwing them all in a closet on end. Store them like that and all bets are off as far as their life goes! Check it out before you go crazy as I did wondering why they failed so frequently!!!

[Mr Spock]

I agree with tech support, the belt should not have caused that. Was there some kind of physical damage to the first transfer roller on the IU in question Causing it to make physical contact, via the belt, to the drum? That would be the only thing that I can imagine would perhaps change the drum bias enough to literally pull the starter out.

I took the transfer belt apart and could not find any visible signs of a defect. so either I had 2 bad iu units or there was an electrical issue with the transfer belt... And believe me when I said I took it apart looking for something wrong.... There was nothing left but scrap metal. It fit in to the iu box when I was done. Like I said it has not been back in 3 months. and we could not get 4 weeks before this.

[Stirton.M]

Strange things indeed.

On a side note, a tech tip for you and others who may or may not have this problem, but we have been having a rash of damaged transfer belt units that are brand new. I think a bunch of chimpanzees or gorillas in shipping and receiving are tossing these around without a care in the world. The damage is limited only to the little plastic bushings that the first transfer rollers ride in. Sometimes only one is broken, sometimes all four on one side, all completely random.

We have started the habit of salvaging these little bushings from old transfer belt units. Basically we just slice the belt and remove a few screws so we can separate the front and back a little bit to pop the rollers out and then a few pressure springs under the bushings popped so we can remove the bushings themselves.

When we pull a new belt from inventory, a quick inspection before we leave the shop. If a roller bushing is broken, we replace it at this point, rather than at the customer site where it can be not only embarrassing that a new unit failed, but an exercise in frustration if there is little room to work on these. As you no doubt have witnessed, there is a lot to taking one of these apart without damaging anything critical.

[Kmdurrin]

Strange things indeed.

On a side note, a tech tip for you and others who may or may not have this problem, but we have been having a rash of damaged transfer belt units that are brand new. I think a bunch of chimpanzees or gorillas in shipping and receiving are tossing these around without a care in the world. The damage is limited only to the little plastic bushings that the first transfer rollers ride in. Sometimes only one is broken, sometimes all four on one side, all completely random.

We have started the habit of salvaging these little bushings from old transfer belt units. Basically we just slice the belt and remove a few screws so we can separate the front and back a little bit to pop the rollers out and then a few pressure springs under the bushings popped so we can remove the bushings themselves.

When we pull a new belt from inventory, a quick inspection before we leave the shop. If a roller bushing is broken, we replace it at this point, rather than at the customer site where it can be not only embarrassing that a new unit failed, but an exercise in frustration if there is little room to work on these. As you no doubt have witnessed, there is a lot to taking one of these apart without damaging anything critical.

But... but... KMBS said I was the only one getting damaged transfer belts! What the hell?!?!