Horizontal Bands and Lines of Grey printing on tops and bottoms of pages

[CJLANDRY]

Hello, 

 I am printing up a planner of 100 sheets of 8.5 X 11 paper, printing on both sides, and I notice that  on some pages a horizontal 1/2 inch band of grey will sometimes print on the top and bottom of each page, sometimes very fine smaller grey lines will appear cross the tops and bottoms.  I have also noticed that very fine grey lines ( almost unnoticeable) will appear on some pages within the bottom three inches of the page.  It's frustrating because I need to have the planners printed without these lines.  I am wondering what I need to do to correct this ?.  

Thanks for your help

[Repairatrooper]

Can you post a sample and be sure to note redirection of feed. I ask this because if you are feeding letter paper long edge first but printing portrait  mode, there can be confusion as the defect is horizontal on the print but vertical based on feed direction. Most common issue we run into on this engine is transfer belt. How many pages are on the printer?

[CJLANDRY]

Hello ,  I attach a photo below.  The printer loads the paper from tray 2 (middle tray), and the direction of feed is left to right.  I have had the printer for a number of years but haven't really started using it until this past month.  The ink cartridges are full and I notice the ink toner reservoir has next to nothing in it.  I am not sure how to determine how many pages are on it.    Thank you. 

[Repairatrooper]

classic signs of problems with transfer belt or secondary transfer roller. Is the firmware up to date? Early models had issues with transfer that were fixed with an update in the firmware.  If belt is too damaged you may need to replace it.

[CJLANDRY]

Hello, 

I have the printer connected to my iMac using macOS Mojave version 10.14.5, and believe I have the latest firmware. Do you think it is worthwhile to try and clean the transfer belt first, or should I just go ahead and replace it ?.  Also , I don't know much about the working of the printer, how does the belt become damaged to the point where it is doing this ?.  Is this considered normal wear and tear, and it just requires replacement after so many pages ?.  Thanks 

[Repairatrooper · Accepted solution]

The reason that his happens, and hopefully this is not too technical is this. On one end of the transfer belt there is a waste transfer bin. Waste toner in the bin is supposed move into the waste toner bottle. However in some cases it builds up in the bin and then backs up and is forced out onto the transfer belt. It is possible to if the wiper blade on the bin has not been damaged to empty the waste toner bin. Depending on the page count on the printer you may be able to convince HP to replace the belt as a courtesy due to premature failure. The other thing to ensure is that the printer sits on a level surface, barring that, the front side (where the paper drawer is) should sit higher than the back, where the waste bin is located. This ensure that gravity assists in moving toner from the waste bin to the waste bottle.

[CJLANDRY]

Ok.  Thanks for the information.  You have been very helpful !

[CJLANDRY]

So I printed up the configuration report for my HP Laserjet M750 and discovered that there is a more recent firmware bundle which I have tried downloading  (FutureSmart Bundle Version 3.9.4 - HP LaserJet M750 Series Printer FIRMWARE), the one I have now is version 3.2.7.  I downloaded the zip file to my iMac , went into downloads and opened the file folder and have two files, a text file and a bdl file. Would you know how I install these ?.  I click on the bdl file and get the message attached below.  Also, I checked from the config report on the pages since last transfer maintenance and it says 25,300,  this is also the same figure for pages since last fuser maintenance.  Total Engine cycles = 15,522.

Thanks

[Repairatrooper]

To upgrade the firmware, extract the BDL file and copy to a USB key. On the control panel of the printer look for I believe device maintenance, firmware upgrade. When selected it will prompt you to insert the usb key into the usb slot on the printer. It will then show a list of valid firmware files on the usb key and ask if you want to install. Once the firmware has installed and the printer has rebooted you can safely remove the USB key. When printer comes to ready, print the config page to confirm that the firmware upgrade was applied.

[CJLANDRY]

So I purchased the HP transfer belt maintenance kit and replaced the transfer belt and rollers ($460 ouch !) and it has printed wonderfully well for the past two days.  I printed up maybe 1000 pages without streaking.  I turned the printer on this morning and went to print one of the planners I have been printing over the past few days,  and I noticed a " crinkling noise" coming from the printer.  I cancelled the print and removed the transfer belt for inspection, and it looks like the transfer belt is creased in certain areas, the few pages printed before cancelling show large streaks.  This is so frustrating, I need to depend on this printer.  Would you have any ideas why this might have happened?.  Is it possible that it was a defective belt ?.  I bought it through a place called PrintersPlus and will be calling them on Monday, but I was wondering if you had any insight or suggestions ?