Printer missing specific lines

[Angus_S]

Office Pro 8730 missing printed lines. Regardless of document content or type, the same 7 lines as measured from the top of the sheet (e.g 2.25", 3.5", 4.5", 5.75, 7", 8.5", 9.75") are missing when printing in black. However, some different lines are missing with other colours. Software and firmware are up to date according to printer info. Ink levels are fine (but not full). Realigning print head several times did not correct the issue. Cleaning the print head several times did not solve it. Unplugging the printer, waiting and plugging in again allowing it to reset did not solve the issue. Anyone have any helpful thoughts on resolving the issue?

[Max3Aj]

@Angus_S, Welcome to HP Support Community. 

Thank you for posting your query, I will be glad to help you. 

Thanks for explaining it so clearly.

Your OfficeJet Pro 8730 is missing specific horizontal bands at very regular intervals when printing, especially with black, even after:

• Firmware and software updates 
• Ink levels are okay 
• Printhead alignments and cleanings 
• Power reset 

Given all that, this behavior almost always points to a physical issue with the printhead, particularly partial clogging or electrical failure in specific nozzle rows. Here's the detailed reasoning:

• Specific gaps at consistent spots strongly suggest some nozzles are either permanently clogged or dead.
• Different patterns with different colors confirm that multiple ink channels are affected, but not identically (different nozzles for each color).
• Alignment and cleaning not fixing it means it's likely a hardware fault, not a simple blockage.

Things You Can Still Try:

1. Deep Clean (Hidden Maintenance Mode)

HP printers have a stronger internal cleaning cycle than the one in the regular menu. Here's how (carefully):

1. From the printer control panel, open the Service Menu.
   • Tap the Home button to get to the main screen.
   • Tap the back button four times quickly (this may vary — some models require you to tap back + home + back + home).
   • If successful, you'll enter a hidden Service Menu.
2. Look for Clean Printhead → then Prime Printhead or Deep Clean.
   • Caution: This uses a lot of ink but can sometimes revive stubborn nozzles.

2. Manual Printhead Cleaning (External)

You may be able to manually clean the printhead if you're willing to open it up a bit more:

• Use a lint-free cloth dampened with distilled water or 50/50 isopropyl alcohol.
• Gently blot the printhead (not the contacts) to soften dried ink.

I hope this helps. 

Take care and have a good day. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Select "Yes" on the bottom left to say “Thanks” for helping! 

Max3Aj

HP Support 

[Angus_S]

Thanks, Max3Aj. I took the print head off and cleaned it as per instructions, but still have the same problem. I don't think it is a blocked jet issue because when I mentioned missing lines, I mean actual lines of text — and that differs depending on the colour. It's not application or computer related as I have tried several applications and 4 different computers (Mac and PC). I feel it is a software/electronics issue in that the nozzles are not clogged but they are not being directed to print. The printer is over 10 years old and repair is probably not worth it, whereas, a new equivalent model will cost about $500.

Thanks for your help.