MX3501N color problems

[gwaddle]

I need some help with an mx3501. Yesterday we got a call that this machine would not print color. When I got there it had started working somewhat. I rebuilt both transfer units and the problem seemed to be fixed. I went back to do a full calibration on it and in the middle of the 46-24, it dropped the magenta. I started over and it seemed to be working OK, then it quit printing all colors. I'm lost. If you cycle the machine off and on the color will start working again. I'd guess I'm missing something simple and stupid but I don't know what. Any help out there?

[mansart]

I would look at the transfer unit, when color is used the belt changes position in order to transfer from CMY drums, when doing BW belt moves away from CMY drums.

[gwaddle]

Still need help on this one if anyone has ideas. We narrowed it down some today. It's not the transfer unit or the magenta drum.

[ZOOTECH]

Check all the LSU shutter blades, they easily warp and block the beam (also, check that the shutters are actually opening).

[bonnie750]

Yep i would go with the shutters to start with. remove them completely to test. there has been problems with the plastic mouldings, little tags on the shutters catching.

[OMD-227]

If this is an earlier model (around 2006/2007) MX3500/4500 series machine, and it has a high count on both B/W and Color, First thing I look at with these symptoms is the Main Drive Unit.
When a 3500/4500 machine starts up OK, then starts missing colors, or during a long print run, they tend to slowly fade off (while the Black is always perfect), the problem is usually associated with the Belt Up/Down clutch failing, or the main drive unit clutch shaft has worn away within the main drive. There is a bulletin on this (I can post it if needed). Its very common.
At the moment, I have been doing 1 main drive unit each month, as all of our original MX3500/4500 machines with high counts are starting to do this problem. I have got the main drive unit replacement procedure down to 15 minutes... fully working!
On the main drive unit, there is a clutch which rotates the transfer belt cam & position. The machine always starts off OK (sometimes immediately shows L4-06 when either the clutch or shaft is completely stuffed), and this clutch drives a shaft running through the main drive unit. On the front side of the main drive unit is a brass bushing with a normal c-clip on it. Over time in high volume machines, this c-clip wears away at the bushing and causes it to be loose or completely fall in inside the machie or main drive. The bulletin has a major modification to the main drive unit to prevent this happening. It is a simple plastic bushing added, and the shaft is longer. It makes alot of difference. The only way to tell if the main drive unit bushing and shaft is starting to errode away, is to remove the main drive unit and look. It cannot be seen from looking through the front.
In all cases like this (and I have done alot of them), I can tell you that most of the time just changing the clutch is not good enough. Even though the clutch part number is upgraded too. The problem will return. If the counters are anywhere near 400K each, and its an early model C-Jupiter1, I can almost guarantee, you are seeing the first stages of a main drive unit failure.
If this is the case, the main drive unit comes in 2 options..... Mechanical unit or complete unit. Please dont order the mechanical unit, as you will spend a good hour removing all motors, sensors, clutches and wiring off the old unit & installing these onto the new unit. Order the complete unit so you get everything on the main drive unit as a new part. Simply remove the old drive unit and install this new one. You will find the only difference is the wiring loom going to the PCU board. It has a small grey loop between 2 pins. If your original drive unit doesnt have this loop, cut the loop off on the new drive unit or you will get L4-31 on startup, as the machine is looking for the toner fan which was added in the newer version machines.

In all honesty, if you can rotate the transfer belt unit quite freely & smoothly by hand when it is out of the machine, then the problem is not the belt unit. If you have colors starting to fade from left to right (but Black is always perfect), it could be the shutters or shutter solenoid, but in all my experience, its most likely the main drive unit.

[OMD-227]

I forgot to say why the main drive unit causes this.......

On a color page, the clutch rotates the belt cam to lower the 3 color transfer rollers down onto the 3 color drums. If the clutch or clutch shaft is starting to errode, the clutch rotates the cam into the correct position, but cannot hold it. Therefore, during normal use, machine vibrations & clutch slipping makes the color transfer rollers move upwards away from the drums. This only happens to the 2 end colors yellow and/or magenta. When the clutch or shaft is in a really bad way, all 3 colors fail and/or L4-06 will appear. The black will always be OK as it has enough pressure within the belt cam assy to hold the transfer roller down on the black drum. If you run sim 6-03 with the front cover tricked and WTB removed for a short period of time, you can sometimes see looking very closely between the belt & drums, the color transfer rollers not lowering enough the longer the test goes for. This is a dead giveaway the main drive unit has gone bad.

[gwaddle]

I swapped out the main drive unit, to no effect. Bummer. Then I replaced all the color LSU shutter units with ones from an MX2600, with marginal effect. It seemed that the shutter lever arm might have been dragging on the under side of one or more of the dv units. I put a little oil on top of the lever arm and everything smoothed out and the copies were good. I know this isn't a permanant solution but it bought me some time till I come up with the real answer. I did notice that the left end of the lever arm lifts up a little when it opens the shutters. I'm pretty sure it shouldn't do this. Any more ideas would help. I kind of burned out my brain this morning on it. Thanks for the help so far.

[OMD-227]

MX2300N, MX2700N, MX3500N, MX3501N, MX4500N, MX4501N

Symptom:

Intermittent colour drop (loss of colour channel) when copying or printing.

Cause:

LSU Shutter operation not working correctly.

1. For Black channel only, check if the LSU Shutter spring has fallen off or the LSU Shutter is catching the DV unit BK

2. For Cyan, Magenta or Yellow, check the LSU Shutter solenoid is working correctly - replace if the plunger operation is weak. Check the 24v supply signal from PCU drops from 24v to approx. 0v when operating (if the voltage only drops to approx 8.5v, replace the solenoid).




** The arm slightly lifting during operation is normal. Dont worry about that. I see that often, even on working machines.
There is a known issue with the Pastel2 shutters, but not the C-Jupiter shutters. I am attaching the details of how to repair/lubricate the shutters (but this is only recorded & mentioned on Pastel2 & C-Jupiter2 bulletins, not on your C-Jupiter1). If you are using the shutters from a Pastel2, do what is mentioned here. The void area is usually through the middle of the page, as the shutter is not opening enough.

[OMD-227]

Also run the shutter test sim in sim 6-01 with the drums & devs removed and the front door tricked. You will see which shutter is under the most load, causing the extra tension on the solenoid.

[Dark Helmet]

Ive had this problem. I was trying to do a 46-24 and some times a color would dissapear. Remove the drums and Dv, pull the shutters out by removing the 4 screws in the front frame and pull the 4 plastic drum holders which have the shutters attached. In the back is a white plastic arm that is pulled by the solinoide and opens the shutters. Pull that out, clean and lubricate with a silicone spray or any lubicricant that will dry. That way dust will not be attracted under the shutter arm and make it hard to open. Be sure to note how the solenoide arm attaches to the shutter arm.

[OMD-227]

Gene,

I'm sorry that I mentioned the Main Drive Unit to you as a 'most likely' cause of your problems, because on the MX3500/4500 series, we have never had a problem with the shutters.

Here's what I know about the shutters....

MX2300/2700 - Small production run in 2008 had a platic moulding fault on the shutters, which would sometimes catch on the rear under-side of the dev unit, causing the shutter to remain open. This causes a repeating line on the back of pages due to laser firing with the shutter open. The problem was resolved by filing down/smoothing off the rough edge on the rear side of the shutter. We never had a problem after sorting this out.

MX3500/4500 - Never had a problem with shutters on the C-Jupiters here. The bulletins on this only mentioned the C-Jupiters due to some minor problems with the solenoid or spring. Never an actual shutter unit problem.

MX5500/6200/7000/6201/7001 - Never had a problem with any shutter on C-Dragon or Venus machines. No mention of bulletins or tech tips.

MX2600/3100/4100/5000 - BIG problems early on with blank pages or certain colors missing. My previous post here contains images from Bulletins on this problem. Known shutter/solenoid problems, solenoid spring upgrade and upgraded shutter part. Worked on ALOT of these models with this problem. Haven't seen it for quite a while now though. Issue is sorted out.


Again, I'm sorry I brought up the main drive unit. I read your original post, thinking this must be main drive as it sounded so similar to our issues here. Didnt even think of any shutter problems, as that series of machine never really had that problem here. I will keep in mind that you guys up north DO have these problems with the shutters.

I'll shut up now........

[Trompeter]

A few weeks ago we placed a new MX-3500N (we still had one) and it worked for a few days. Last week we placed some opties (sorter/fax) wich were in backorder.
This week the customer called that he had problems with the start of the print (it changed about 16 mm) en had blanc copies in color mode (black was ok). It didn't print color at all.

Sharp adviced to replace the laser unit or the mfp-board (????).

You don't believe what causes this problem. I told my engineer to disconnect the fax-unit en after that all problems were solved. He re-installed the fax unit and it still worked.

We had in the past several strange problems wich where caused bij installed fax-units.