Mpc7500 / 6000 low density possible cure!

[turbojetboy]

I have been experimenting with a mpc7500 that has constantly from new lost its black density after 10k to 15k. This is a well known issue with this model and to date ricoh has not been able to provide any answer. Well this is what I have done and it seems to work. Based on my belief that Ricohs attempt at trickle feed development is a failure I have modified this particular machine - removing drive to the trickle feed out auger. The result of this is that the machine is no longer driving out developer (which it does) any time the developer is rotating. The machine in question has since maintained density and the copy quality has remained steady. Opening up the dev has shown that the height of the developer has remained more consistent, whereas before the dev was down about half of the initial fill. There are no down sides to this mod that I have seen, in fact I expect to see a reduction in waste toner and also a reduction in new toner usage.

So here is how I did it, remove the one way cam that drives the trickle auger from the front of the dev! Thats it. It takes about 5 minutes and you only need to remove the front drum plate to access this part. See pics below. The third picture shows how it looks before you put it back into the machine.

Please let us know if you try this mod and how it goes for you!

Incidentaly I also feel that there is no where near enough carrier in the toner bags to keep up with the amount being depleted from the devs.

Cheers.

[Lagonda]

Our in-house MP C7500 is the worse offender for this. The reps use it for pumping out flyers so it does long runs with high toner coverage. It swallowed one dev change in under 10k then we swapped K dev unit and so far its behaving its self.
One thought that did occur to me was if you stopped the old developer getting out and are still stuffing new developer in, is there a chance it will over fill and lock up?

[turbojetboy]

No sign of overfilling or overtoning, I dont think there is anywhere near enough actual developer coming in to cause this problem - however this is still early days with this mod and time will tell. My trial machine has performed faultlessly for 22k and 1 month now.

[Vulkor]

PLEASE Keep me up to date on this. I'm very interested. You are doing this only on Black??

[turbojetboy]

I am about to perfrom this mod to another MPC7500 that we have had no end of trouble with all of the devs depleting - so I will have one with K only mod and a new one with all devs (and this one works very hard, high coverage high volume colour runs). Will keep you posted.

[Rajrajraja]

I am about to perfrom this mod to another MPC7500 that we have had no end of trouble with all of the devs depleting - so I will have one with K only mod and a new one with all devs (and this one works very hard, high coverage high volume colour runs). Will keep you posted.

Hi,
Can you update the status adout the machine.!
Regards,
Raja.

[turbojetboy]

Well the original machine (K dev only modded) has not had a call since (which is a record for this customer), so I will be dropping in next week to check over it. On 23rd Oct I attended one of our big print shop sites that have 2 7500's side by side doing virtually identical work and meters, both have given us no end of trouble with density loss and we have had to change devs approx every 15k - needless to say owners are giving us that look every time we are there. This is the perfect site to test, so I changed devs on both machines, put in fresh waste bottles, charge rollers and set each one up exactly the same EXCEPT that only one has all 4 devs modded. I will be checking on these machines weekly and this will be the acid test. Also I will be able to guage whether there is a reduction in waste toner. So stay tuned as I will be updating this regularly. Our national support centre has taken a keen interest in this, I think secretely they would love to see this problem solved without actaully having to do anything themselves.

[Rajrajraja]

MPC7500

Please update,
regularly..
Regards,
Raja

[stephend]

Well the original machine (K dev only modded) has not had a call since (which is a record for this customer), so I will be dropping in next week to check over it. On 23rd Oct I attended one of our big print shop sites that have 2 7500's side by side doing virtually identical work and meters, both have given us no end of trouble with density loss and we have had to change devs approx every 15k - needless to say owners are giving us that look every time we are there. This is the perfect site to test, so I changed devs on both machines, put in fresh waste bottles, charge rollers and set each one up exactly the same EXCEPT that only one has all 4 devs modded. I will be checking on these machines weekly and this will be the acid test. Also I will be able to guage whether there is a reduction in waste toner. So stay tuned as I will be updating this regularly. Our national support centre has taken a keen interest in this, I think secretely they would love to see this problem solved without actaully having to do anything themselves.

I'm just ears, to hear how this mod will end. I think you have the perfect environment to test it. I tried to suggest the same thing since this machine start causing problems, immediately after official launch but I found a wall of negative attitude in front of me. Good luck

[slot]

just found this post a most interseting idea i hope it works i have never looked at this problem this way but it make sence many thanks for keeping us up too speed

[Jomama46]

Trickle feed developer? Is the toner partially developer?

[Lagonda]

Trickle feed developer? Is the toner partially developer?

Yup, 10% of each toner is developer. The theory is that as its continually renewing the dev the copy density remains even. Well that was the theory!

[Vulkor]

Any News on this??

[turbojetboy]

I will be writing up a full report soon, however I can tell you that I have been watching these machines (the 2 moded ones) and neither of them have had any problem or call since! I also know that both of them have completed over 40k each. I will wait at least a month and then open up devs and have a look etc. I can tell you that quite a few of our other techs have performed this mod and we have seen no problems at all!! I am not going to say this is 100% cure BUT it does seem to work and has no drawbacks and is very easy to implment. Stay tuned.

[tcs04]

TOP MAN!!

Will be trying this on the 2 machines giving me trouble as soon as I can get to them!!

Incidently, One thing that does cause all Ricoh colour machines to run slightly grey on B+W copies is the default original type setting of "text / photo" mode. changing this to "text" and locking as default will also give a 5% -ish increase in full black solids.