MPC 4500 Low Image Density

[Noj7373]

I have a couple MPC4500's with Cyan and Maginta toner density keeps going low. I have cleaned the 7 density sensor above the transfer belt, forced toner to bring up density and ran ACC and Force line adjustment. Brings Image density up for about 2 weeks. I have removed the laser shutter and updated all firmware. Machine only has 60K in color clicks. Tech support has had me clear Engine Memory and did not help. I believe that its not calling for toner soon enough. Any Ideas would be helpful.

[cobiray]

You might have faulty toner pumps or clogged tubes. I've had a few that need the tubes cleaned out or replaced.

[Noj7373]

Density comes up when you run forced toner, Toner seems to pump fine.

[schooltech]

How quickly is the density returning to normal? As cobiray said, they may be clogged, but not completely clogged, as the density will return but only after a force toner add.

But, you stated that it will stay for about two weeks, so I'd also be inclined to think that the pump supplies are ok, although I wouldn't overlook the toner supply maybe being just a bit clogged. Because it is not with all four colors, I'd tend to think there would be just a bit of build up in the supply system. During these two weeks, what is the approximate volume of the machine? Is it possible that the ratio of colors placed on the paper isn't enough to use the cyan and magenta very often (although they're used a lot for colors anyway?) Just throwing it out there.

[TonerMunkeh]

Might also be a bad set of toners, I've had a few bottles that have settled in storage and don't work too well in the machines.

As Cobiray said, whip the controller board off the back of the machine and vac out the toner pipes and pumps. Won't do the machine any harm and it might cure the fault anyway.

[largo]

I HAD IT ONCE ALSO

REPLACED io BOARD
DEV BOX
PCU
ID SENSORS

NOTHING WORKED

THEN SOMEONE CAME AFTER ME AND CHANGED THE SENSOR AT THE TONER PUMP AT THE REAR AND IT WORKED AGAIN

[cobiray]

I've also had one that whipped a tech for awhile and it was just dirty optics. Make sure you've cleaned them before throwing parts at it.

[Noj7373]

I went around to a few of these machines today to check on them. I looked at VT and Vref and in most cases VT was anywhere from .08 higher to double Vref. I suspect thats the problem but I dont know how to fix it. Did Engine clear on one per TS but they forgot to tell me to back up on SD card and threw backround shading off. If anyone can tell me how to clear the engine properly and which SPs to change after Engine clear it would very helpful. I am a fairly new tech, only a little over year in the field and even less with color.

[iMind]

There should be a SMC sheet under the misfeed instrution on your front door just put in all the values as no sheet.

[Noj7373]

OK, So I need to reset all of the the SP on the "Birth Certificate", One of them I know has none. What should I do in the case?

[Noj7373]

Ok, a little update. Went around to 3 other MPC4500 that I have, Printed out a ACC, all of them were lite(Mostly color lightness). Went in to SP mode and checked Vtcnt(sp3221 I believe) Most were up near 3.8V and Checked Vref(sp3222 again I believe) and they were all around 2V. Troubleshooting says Vt should be .1 to .2 V BELOW!!!! Vref. I had Tech Support send me a SMC report from one of their testing Machines and it showed the samething. So is the troubleshooting and detailed discription sections wrong, or are we doing something wrong. Tech support basically said I had done everything they could think of and to replace all PCU's with Dev and transfer belt assy. That could get kinda of expensive and seems strange that all of my MPC machines are having the same problem. Anymore Ideas would be great.

[Marius]

[slot]

you may need to check all the default settings on the data sheet that comes with the copier we have had a few that needed resetting back to defaults on the cq settings

[fitsy.13]

I have a couple MPC4500's with Cyan and Maginta toner density keeps going low. I have cleaned the 7 density sensor above the transfer belt, forced toner to bring up density and ran ACC and Force line adjustment. Brings Image density up for about 2 weeks. I have removed the laser shutter and updated all firmware. Machine only has 60K in color clicks. Tech support has had me clear Engine Memory and did not help. I believe that its not calling for toner soon enough. Any Ideas would be helpful.

i had a problem with the same machine it turned out that someone had been playing with the settings and changed the suply from sensor controled to pixel just check that first as i put new pumps in thaqt didnt need it

[E Winter]

I had this issue when the machines are running with very low color volume. I did some good experiences whith 2x toner add + td init, too.