MX5001 back half of black images greatly faded

[Sam Tofu]

Customer had labels stuck on primary transfer. Able to get working OK but had small gouge in it where customer tried to get label with fingernail. Replaced with new unit.

Replaced Black drum and MC kit as label on drum also. (Had 77K on the black meter). Did sims for new belt and for drum change. Ran 100 test copies -all OK.

4 days later got call saying copies from front to back-(not lead to trail) having the back half very faded (evenly so)...~ back 1/2 all faded the same level (barely readable).

Swapped Black Process Unit with Cyan Drum unit and still same issue( still back half faded).
Also Note, if run one color such as cyan or green prints then print OK. Other misc notes:Cleaned LSU cover glass also with drum out, lifted cover and viewed LSU cover glass with flashlight.
Additionally, prints are then same whether on platen,scan or internal test prints. Just in case - changed out black developer and recalib. with sim. settled at 128. Also to rule out various misc, also checked toner motor.

Thought maybe cam on belt acting up. Since still had old belt unit so put it back in. THEN entire page printed faded??? So put the (new) belt back in, then again only back to only 1/2 faded. (and did screw belt into place)

Checked rear contacts etc. Then once again, put back in old belt and again full page faded. Checked the machine mounting guides for belt - they are OK. Swapped back to new belt and again 1/2 faded. Belts is seating on frame as should be.

This really has all 3 of our techs stumped. NEED HELP. customer is a large 40 person office and uses this for their only incoming fax machine (they get about 10 important faxes per hour) Also they print ledger color maps etc.& without a back up machine for ledger prints) Thanks for assistance.

[igi]

Re: MX5001 back half of black images greatly faded

hi
S.T
did you try just the belt or the whole belt unit

[Akitu]

Re: MX5001 back half of black images greatly faded

There was a bulletin released in November of '10, stating there was an issue with the black toner splattering on the rear side of the BK DV tank, making the main charge dirty and causing an increase in drum potential, leading it to pull excessive amounts of DV out and cause blank areas and other print irregularities. If your machine was produced before November 2010, use part PSEL-0966FCZ1 and replace your DV, problem should resolve.

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

Thanks for input.
Yes we replaced the entire belt unit (did not rebuild).
Checked for toner leaking in back as well as proper toner dispensing.
Since we did think a possibility of dv exhausted with maybe improper toner fill - we did replace developer and recalibrate. Doing dv sim yielded a good setting of 128.

[Dark Helmet]

Re: MX5001 back half of black images greatly faded

I would confirm that your LSU shutters are opening properly. Also check in sim 6 the operation of your transfer belt and watch it rotate with the front door open. If the machines has a old style clutch that operates the transfer belt cams, it can fail or become intermittent as the wires on the clutch can move around and short out.

In the mean time you could setup inbound routing for the customers faxes until you get the problem fixed.

[copyguy1]

Re: MX5001 back half of black images greatly faded

Just had a b401 doing same thing replaced belt unit and same problem, May want to look at the transfer roller in unit not being seated correctly. We put a belt unit in from a working machine and it was fine.

[Dark Helmet]

Re: MX5001 back half of black images greatly faded

Just had a b401 doing same thing replaced belt unit and same problem, May want to look at the transfer roller in unit not being seated correctly. We put a belt unit in from a working machine and it was fine.

Hi copyguy, the slider arm that pushes the transfer roller down probably broke free of the frame of the transfer unit in your case.

Ive seen the exact same thing on the 401 as described. The white plastic slider twists and does not push the roller down to the drum and you get half the image missing. Ive been told the factory has made a stronger post to support this slider.

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

Thanks Lawrence
We set them up with a loaner MFP for faxes.
I will go out tomorrow and check out your other suggestions.
ONE thing that came up today was I ran a 44-6.
I got a K-HV-ERR (K high density process continuity abnormality). So I was thinking about pulling the Hi Volt board and checking the contacts etc.

Hopefully some of your suggestions will do the trick.

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

Sort of shooting in the dark on the err that came up when running 44-6
K-HV-ERR (K high density process continuity abnormality)

Anyone have idea what this relates to? We are assuming it is a direct tie in to the fading issue

Thanks

[mojorolla]

Re: MX5001 back half of black images greatly faded

I would do the high voltage adjustments in SIM 8. This will tell you if the HV board is bad or out of calibration, both transfer and charge. I have seen a few of these drift from time to time. Do a panic stop and see what the image looks like on the IT belt. If it is good on the belt, you have a transfer or pre-transfer issue. Density sensors clean? On a 20 amp breaker?

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

Ran Sim 8 - all readings looks OK
With door open, checked transfer belt shifting - main trans belt can be seen to shift OK from black to color to neutral position.
Panic Stop results show image OK on Drum. So problem is in transfer of image to belt.
After initial replacement of Transfer belt , imaging was OK for ~400 copies.

Again strange thing here is that using the two different belts - one copies OK on the front of belt and a greatly faded image only on the rear or rather back 1/2 of belt.
Then on the older belt that had the fingernail deep scratches, (Which was making OK copies before initially changing ) is now producing greatly faded copy on entire image.

Switching belts back and forth into the machine produces the same pattern i.e faded pattern stays with the swapping of belts.

SO again with test SIM 8 (see above) seems OK Yet with 44-6 we get hi volt density process error.

[divad2k1]

Re: MX5001 back half of black images greatly faded

I think your next step would be to replace the high voltage pwb.

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

that's where we where leaning thanks for the "vote"/help!

[blackcat4866]

Re: MX5001 back half of black images greatly faded

Just to throw in my two cents:

The reason the machine is giving a K_HV_ERR when performing a 44-06 is due to the fact the image is too light on the belt, when being read by the ID/Calibration density sensor. As the patches on the belt are read by 2 different sensors (one for CMY, one for K), the density sensor is not seeing the patches on the belt, therefore thinking there is a high voltage issue.
Most of the time, this problem is not actually related to a high voltage problem at all. There are many known cases of the Primary Transfer Belt charge PWB not working correctly, especially if the image is OK on the drum (indicating that the MC/HVT PWB is OK). If the transfer charge PWB is not working correctly, the transfer of image from drum to belt is low, then the density sensor cannot read the patches on the belt during forced process control of 44-06.

The primary transfer charge PWB is the same part number across all MX2600, 3100, 4100 & 5000 series machines (RDENU0089FCPZ). This part number has not been upgraded or changed.

If the image is poor on the drum, then the problem is the MC/HVT PWB, which has been upgraded many times. Reading the post, it seems that the image is OK on the drum, so it probably is not that.

The part that troubles me the most is that you keep trying the same two transfer belts. There is a possibility that both of these belts have issues. If one of them is giving a complete light black, and the other is front side frame OK, it sounds like problems with the transfer roller tension springs in the belt unit itself. I have seen cases where if one side tension spring has fallen off, the transfer roller lowers down onto the drum at an angle, therefore giving a light transfer on either front or rear side, depending on the missing spring.

As I read this fault, I'm betting you either have an issue with both of these belt units, or the transfer charge PWB. My recommendation is to either grab another belt unit (preferably new), or if possible can you get me a scanned image sample? I'll be able to tell what the problem is straight away.

=^..^=

[Sam Tofu]

Re: MX5001 back half of black images greatly faded

MX 5001 Scans.pdf
RE the attached. The all faded is the old (worked when took out) belt. Half faded is brand new belt with 400 OK prints before issue.

NOTE: Upon your suggestion blackcat (BTW -THANKS for all the info) I did check new belt and found that the metal rod that hangs under belt near black drum had one side where the rod snaps into place cracked. We are ordering a warranty replacement in am.

HOWEVER, I checked older belt for all contacts, springs, cam action all very carefully 3 times and couldn't find any issues with it. Made certain the density sensors are clean. While I am glad to find out one of the belts logically would cause image problems, and hope when I put the new one in - all will be GREAT.

I have some still "oh no" reservations due to the other older belt having the image issue that showed up the same time the newer belt had issues. BTW, when I took that older belt out initially I carefully re-packaged it in the packing of the new belt to protect it as an emergency backup.

This afternoon -did one more panic stop. Image on drum looks "perfect". Image transferred to belt looks just like the one that ends up on the copied paper.

So if new belt doesn't take care of issue it seems the transfer charge PWB is the next step.