ADF takes paper, but does not copy or scan - bad 4 pin FPC cable

[lighttech3490]

I don't have a problem, but a solution for a common problem that I had, and could see other people having the same issue with no resolution short of exchanging the printer. 

Model: Officejet Pro 8034e.

Symptom:  When placing a document into the ADF (face up) it would show on the display "document loaded."  If you copy or scan, it will take the paper (original) and run it through the ADF, but it would end with an error saying "Reload Document - Failed to pick up...."   Scans and copies using the glass worked fine.

Solution:   Replace the 4 pin flat cable that runs from the main PCB up into the ADF feeder.  It is a challenging job, and it may be easiest just to replace the scanner lid assy which includes the document feeder.  The flat ribbon cable goes to a photo interrupter that I believe tells the printer that paper is presently running through the rollers.  All four connections were open.   It is not to be confused with the interesting sensor that is used to detect when a document is loaded.  They actually use the scanner itself to "see the lever" when a document is first loaded.  Once the paper starts to go through the rollers, another lever moves that changes the state of the photo interrupter.  I forget if it is blocked or clear without paper.  

Why It Fails: Most likely the bending and flexing of the cable whenever you lift the lid to scan a document on the glass.

Luckily I had spare parts laying around from previous printers that were not economical to repair, and was able to fix it.

[Alden4]

Hi @lighttech3490,

Welcome to HP Support Community.

Thank you for posting your query.

That's quite a detailed solution you've discovered! It sounds like you've really delved into the mechanics of your printer to diagnose and fix the issue. Replacing the flat cable seems like a more cost-effective solution compared to replacing the entire scanner lid assembly. Plus, understanding the underlying cause of the problem helps prevent future occurrences. Your explanation also sheds light on how the printer's sensors work to detect document loading and feeding, which can be helpful for troubleshooting similar issues in other models. Thanks for sharing your expertise!

Take care and have a good day.

Alden4

HP Support 

[lighttech3490]

Hi Alden, 

Thanks for the compliment.   Changing the flat 4 pin cable is definitely cheaper from a parts price perspective.   However, taking apart the ADF to the point where you can get to the cable was labor intensive.   If there was a service manual showing the exact procedure, it probably would go much faster.  Does HP offer service documentation and internal spare parts?  If so, please send me a link.

Thank You,

Craig