Printer Rattling Noise

[mddiesso]

Product: inkjet 960c
Operating System: Mac OS X 10.6 Snow Leopard and older

Printer makes ratting noise before printing. I used a flashlight to look at the service station and noticed a loose green plastic part under the service station (black ink rest location).

I opened the case and when moving the service station up and back to examine the part, an identical green plastic part appeared, loose, under the color location.

Both pieces are rectangular with rounded corners; one face is smooth with two small projecting points perpendicular to the face; the other face has a "well" in the center and a number in one corner (8S, or S8, or 85).

Does anyone know what these pieces do and where they go?
Do they go horizontally under the service station? If so, well-face up or down?
What do the projecting points do?
DO they go vertically behind the service station?

I removed both pieces and reassembled the printer and tried it: it printed perfectly without ratting, but I am hesitant to use it without replacing the pieces.

I took a photo of both pieces (front and back views): (HOW DO I ATTACH A PHOTO?)

[Repairatrooper]

Add photo by clicking the camera icon. All photos are moderated so it will not display when you first post but will show up once a moderator has approved it.

[mddiesso]

I have enclosed a photo of the two pieces:

[mddiesso]

I think I figured out where the two pieces of plastic/rubber go and solved the rattling noise issue.

The pieces seem to go UNDER the cleaning/service station. There are two wells in the service station, one for the Color on the left and one for the Black on the right. The pieces go under the station and align with the holes.

Open the lid and let the print heads move to the left and unplug the printer.

Then remove the top of the printer (two #10 torx-head screws, and two tabs in the back of the printer, and two more tabs in the front of the printer) After releasing the tabs, lift the top section onto its side (there are wires connecting the top to the base that I chose to leave untouched).

On the right is the service station. It moves up and back and uses a spring to return it to position (MY GUESS is that it moves up and back several times before printing to clean the print heads - it's plastic mostly and so it rattles).

The two pieces of hard-rubber (they aren't really plastic, it seems) fit under the service station mechanism. MY GUESS is that as the printer ages, the rubber dries out and shrinks and loses adhesion to the underside of the service station and then fall off!

The hard part was putting them back in position and making them stick; there isn't enough room to fit them under the station using your finger.

Each piece has two prongs on the back, so I made a tool out of metal flashing that has two small holes drilled to align with the prongs; that tool allowed me to slip the pieces under the service station. To make the pieces stick, I first placed a very small bead of caulking (plain old window caulking) around the edge of each piece and then used the tool to insert it under and up, The caulk acts as an adhesive to hold the piece in position.

After letting the caulk dry over night, I re-assembled the printer and reconnected it to my iMac. I had trouble getting it to work properly, but it didn't rattle any more - success! However it kept indicating a paper jam, i.e., it would start printing, then halt with the paper jam light blinking. It wasn't until I rebooted the iMac that that problem disappeared.

It now works quietly.

MY GUESS is that the rubber pieces perform two functions:

1. they keep any ink drips from pooling in the printer base;

2. they act as stiffeners for the plastic service station and  make it rattle-free.

I'll see how long the fix lasts; if the caulking doesn't hold I might try glue. That will be a problem for another day.

I do not work for HP and this solution is of my own devising; use it with caution.