I’d already made the repairs discussed in the past (relocate gear on spline with adhesive). The gear hub (the part between shaft hole and the bottom of the gear teeth) is undersized and can’t withstand the expansion force created by the shaft spline. The gear in question, the one that slips off of the spline on the shaft, is the planned obsolescence component on this printer. I’d purchased another one of this model (for parts only - $25), and have used it to replace a number of components. I’ve used this printer for lots of photo proofing/printing (as well as regular printing), and have invested more than enough time and expense installing a CIS System and calibrating color output many years ago. Specifically, I’m dealing with a C309A Photosmart. Seems this discussion has strayed to a number of different models it may be a somewhat universal design however and the issue probably applies to more than one. If the rubber pick-up drums still slip, repeat the cleansing operation. Print a test page (e.g., a blank Word document to avoid wasting ink). Let the water evaporate and reassemble the duplex unit. This is tricky since you need to reach into the printer from the back (left). Now take another moist Q-tip and swipe the rubber-covered grooved paper pick-up drums clean in a similar fashion. Rotate the axis upward (only possible way) to clean the next section of the 4 rubber drums. Clean these with a Q-tip moistened (not soaked) in clean water, and move from left to right. You can now see 4 rubber drums on an axis. Unplug the printer's power cord, detach the duplex unit at the back (push to the left and pull back to disengage the unit from the printer). If you see the paper pick-up drums slip on the paper, then you may have better luck. Here's a written summary based on my experience: There are image and video instructions available from HP. Scenario 2: the pick-up drums do roll, but they slip on the paper Probably the entire printer must be torn down, and I don't expect you will be able to easily fix the excess play on the paper pick-up mechanism that drive the rubber rolls when pressed on the stack of paper. I suppose that because of excess play (programmed obsolescence?) eventually the cogwheels that drive the drums will slip. When the drums touch the paper, they simply don't rotate. When lifted, you will be able to rotate these drums in one direction. When printing, they are dropped to the top of the paper stack and will engage to separate the topmost sheet off the stack. When not printing, these drums are lifted. It looks like there is too much play in the paper pick-up unit (at the rightmost end inside the printer) on which both pick-up drums are mounted on a single arm. You most likely hear a grinding noise of plastic cogwheels slipping when the printer tries to feed a sheet of paper. Scenario 1: the pick-up drums do not roll, you hear a grinding noise Thanks much for steering me in the right direction. My printer had little use as I have a second one that I use for everyday printing, so, wanted to save the hp 310 as my good scanner/color/printer.

Now works great! Hardest part was manipulating the dabbing of the epoxy on the spline due to working with mirror image. Waited until next morning to try printer. Very carefully slid the gear with fingers back on the shaft spline viewing that it was centered on the mating gear.

Mixed some two part epoxy and carefully dabbed small amount on the shaft spline until about 100% coated. Then slid the gear down & off the spline. (can move the gear by hand back in line with the gear train and try once to see if it fixes problem). One small plastic gear slid off the steel shaft 'spline' not engaging drive train. Taped drop light to now top of printer looking at the mirror/gear train. Positioned small flat mirror angled on its edge to view gear train.

Hp photosmart 7525 printer reset button