Hello... I feel a bit foolish posting about this, as it might seem insignificant. My 3100 lost a tiny but necessary part - it is called the "Carriage Rear Bushing" (HP #Q5669-60687). Piece of plastic, about 3 inches long, each end going loosely into a hole while from its center, protrudes a 'bump'. Can be found at the rear upper part of the printer carriage. Aside from playing a part in oiling / lubrication (appears so), one of its functions is to maintain the carriage at a certain height, by sliding along a metal rail as the carriage itself goes back and forth...
Anyway, I am frustrated at not being able to find this part; HP itself of NO help. One place that had been helpful some months ago on a different part (belt) told me that HP "has been losing it...". Another said that HP does not even stock its own parts, and might not have it for months, etc... The printer is sitting here past 4 days, and for something that costs less than $20, I can't do any printing. Short of me fashioning some sort of plastic 'replica' for this tiny part, any suggestions please as to dependable parts suppliers or...? TKS, Henry