Officejet K550 Pro: Paper Feed Problems

Question

About a year or two ago, we purchased a K550 unit for our office, and 3 subsequent units for employees' personal use.  At first, everything went great - it was the best inkjet printer I or my staff had ever owned!  After a month of great service, my staff and I recommended this product to customers demanding a printer with low cost of ownership and fast, high-quality printing.  However, after about 3 months of service, all of our units began developing paper feed problems in about the order they were purchased, depending on their usage (the older units first, unless they were used more than other units).
It started with an occasional failure to pickup a new sheet during a print job, slowly progressed to having to hand-feed the printer to get it started on a job and supervising the printer throughout the job to clear the occasional feeding problems during the job, and erupted into a continuous hand-feeding of every sheet of every job through all of these printers, all the time.  We immediately replaced, at our cost, all of the 15 customer units, 3 employee units and 1 internal unit that were purchased by us or on our recommendation with other HP devices, even after several customers willingly contacted HP and were sent warranty replacement new and refurbished units that also failed.  The only three K550 printers that remain in service with us or our customers (one in our office and two others with customers who requested to keep the units we replaced) fail to pick up any paper out of the main tray an astonishing 93%, 98% and 100% of the time, respectively.  This is not an exaggeration, these are documented numbers rounded down when applicable).
I've perused many online sites, forums and websites on this topic - both professional and non - and found this to be a common problem with what seems to be a very great number of these units.  Some folks also mention a problem with the K/Y (black/yellow) printhead, but neither I nor any of our customers have experienced this problem.  In solving this feeding problem, we've tried different brands, weights and chemical makeups of paper (HP paper works well, but Staples brand paper of standard weight and 97 bright works best), tried different loading strategies for each paper type (such as fanning the paper before loading and before printing, light, moderate and heavy loads in the standard tray), tried installing a duplexing device (HP OEM of course), tried installing the larger paper tray (also HP OEM) and flashing different firmware supplied by HP - all to no avail.  None of the units have any aftermarket parts, kits, ink cartridges or printheads - everything installed and used in these printers is OEM, except for occasional special papers or label sheets.  So where does this leave us?  More importantly - where does this leave my customers who I prematurely recommended this product to?
We're looking for a solution from HP.  We've tried customer service and have opened several issues without resolution.  I'm tired of my employees and myself dealing with this issue only to be told how to load paper and to flash the same firmware on the same device for the third, fourth and fifth times.  We have 16 defective units in storage and 3 units in partial service for a total of 19 units.  Accounting for these 19 units:  we lightly use 1; we sold and supported 15 of these within our customer base and 3 to our employees, all of which we replaced with other HP products (again, at our cost), and 2 customers decided to keep 1 defective unit each.  As a result, both myself and my company are out big money because of this issue.  We replaced all of our supported K550's with other HP devices only after unsuccesfully attempting resolution with HP.
If there are replacement parts that address and resolve this conflict available, where can I obtain them?  If there is a simple remedy, what is it?  What can we do to mitigate this situation and yield a positive outcome?  The K550 is an outstanding printer in terms of speed and print quality, unfortunately its unreliability due to poor feeding performance and need for constant supervision and user intervention doom this model to the component recycler's scrap heap.  Do you have a solution?  Are you experiencing the same problems?  I want to know!

Answer 1

So, I just typed this nice, long post about my SOLUTION to this problem, and apparently the forum didn't like it and deleted it.  I'll have it up in the next couple days.