I think I have narrowed down the problem to be an issue that is only present the first time I print in the morning. After a bad print I did 2 cleaning cycles and now it prints just fine. Talked with HP again and they guy I spoke with told me to switch my sleep time from 30 mins to 120 mins (not sure why). He said that there was something with the new firmware that needs to allow the machine a longer cool down time (sleep time) in order for air to not be introduced into the print heads. The cool down time didn't really make sense but air in the printhead did. Anyone had issues with prints only on the first try in the mornings? Anyone else heard of an explanation similar to what HP gave me?
Haven't seen or heard any of these issues. Then again, I am not running the latest firmware either. I am hesitant to upgrade the firmware when the printer seems to be running just fine for now.
I guess if there ever comes a time when I'm "forced" to do a firmware upgrade due to specific issues, then I would do what I need to do, but to me it sounds like an upgrade now would perhaps cause new issues??
And just my opinion... $500 to replace the part doesn't sound too unreasonable considering how complex it looks to do yourself. Plus, if anything goes wrong when you do it yourself, it could lead to more expensive fixes. If something goes wrong when HP is doing the replacement, well then, it's their issue, not yours! Just food for thought!