How to Fix HP Officejet Pro 8600 Paper Feeding Problems After Carriage Replacement

Question: I have an HP Officejet Pro 8600 printer with a paper feeding issue. The original problem was that the ink carriage’s bottom rubber attachments broke. I replaced the print carriage, and although the printer powers on and cycles, it now fails to feed paper into the printing path, displaying a paper jam error. A few times it fed paper, but it only printed blank pages. The rollers and duplexer have already been cleaned, and the plastic covers are disassembled, but the problem persists. What could be wrong, and what part might still need replacement?

1. Paper Jam and Feeding Errors

When the printer attempts to feed but fails, throwing a paper jam error, the issue can often be traced to the pickup roller assembly or the separation pad. These parts are responsible for pulling sheets correctly into the paper path. Even if the rollers appear clean, they can lose their grip due to wear and may require replacement.

Also, check the paper path sensors. If a sensor is dirty or misaligned, the printer may falsely register a jam even when no paper is stuck. Sometimes, compressed air cleaning can miss sensor areas, so a close inspection with a flashlight is recommended.

2. Blank Page Printing

If the printer occasionally feeds paper but outputs a blank page, the problem is likely not only mechanical. Since you replaced the carriage assembly, there’s a chance that the flex cable connections between the carriage and the motherboard are not seated firmly. A loose or partially damaged ribbon cable can prevent data from reaching the printhead, resulting in blank output.

Additionally, even though you mentioned that the printhead was replaced a few years ago, it’s worth verifying that it is still functional. If the printhead is clogged or electrically failing, it can also result in blank pages. HP printers sometimes display vague errors, so a faulty printhead may only manifest as blank printing without a specific error code.

3. Alignment Between Carriage and Encoder Strip

The encoder strip (a transparent plastic strip with fine markings) ensures accurate carriage movement. If it is smudged, stretched, or misaligned during carriage replacement, the printer may mis-time feeding cycles and fail to start printing. Carefully clean the strip with a lint-free cloth and ensure it is taut and properly seated.

4. Firmware and Reset Procedures

After major hardware replacements, some HP printers may require a semi-full reset to reinitialize carriage alignment and clear old error states. You can usually access this through a special button sequence or HP service menu. Updating the firmware may also help, especially if the printer is stuck in a recurring cycle of feed/jam miscommunication.

5. Possible Additional Parts to Inspect

• Feed Roller Assembly / Pickup Roller Kit – often the root cause of repeated jam errors.

• Paper Sensor Assembly – if misaligned, it will keep reporting false jams.

• Formatter Board or Carriage Cable – if communication between the board and carriage is inconsistent, the printer may feed incorrectly and fail to fire ink.

Printer repair can be complex and requires hands-on testing, so we cannot provide full troubleshooting remotely. BCH Technologies does offer an in-person evaluation and repair service (https://bchtechnologies.com/printer-repair-service) through our local diagnostic facility. Because of high demand, repairs are performed on a first-come, first-served basis and may take several weeks. We repair both full units and individual components, with clear instructions provided. However, we recognize that our services may not always be the most economical, so we encourage you to also explore self-help options. A good starting point is researching online resources and checking our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon on the channel’s page to quickly find videos related to paper feeding and HP repair.

Thank you again for reaching out to us with your detailed description of the issue. Your engagement is appreciated, and we’re always glad to provide technical guidance to the printing community.