M604 unable to remove Tray 2 cassette

[S1N1STAR]

The Tray 2 cassette on our M604N was recently forcibly removed which irreparably damaged the cassette.  I have since replaced the cassette but it cannot be removed unless you reach in from behind the printer and trip the paper lift into the down position.  There were some extra parts from the initial damage that are not part of the cassette but I have been unable to find any location correlation using online parts diagrams.  I suspect the parts work with the cassette release but must be part of an assembly.  In the past I was an HP printer tech (CX through 4200 series) so am comfortable with working on the machine but being unfamiliar with this particular print engine and not having good documentation is proving a bit of a challenge.  I am attaching a photo of the part in question which doesn't appear damaged and likely needs to be snapped back into place.  The spring may or may not actually belong, I placed it as you see while I was looking for its home in the printer.

[Repairatrooper]

I checked one of our 605 (identical to 604 save speed) and the part you are showing is not anywhere in the tray cavity that I can see. If you are going to self maintain, check out feedroller.com, you buy manuals there for a couple of bucks, worth the investment.

[S1N1STAR]

Thank you for the feedroller.com info, I got the service manual but haven't yet received the troubleshooting manual.  Looking through I haven't found the mechanism or sequence that drops the paper lift when removing the cassette.  I believe that's where the problem is whether related to the pictured part or not.  As I mentioned I have to reach into the cassette from the rear opening and manually drop the lift, then the cassette can be removed.  The normal "lift and pull" action does nothing nor does any other wiggling from the front.  Of course, as one of my employees discovered, if you yank hard enough it will come out... in pieces.

[Repairatrooper]

There is no "mechanism" per say on the tray. When you insert the tray the gear on the tray pushes back on the lift motor (red arrow) which lifts the tray into position. When you pull the tray out, the motor disengages and gravity causes the paper tray to drop. If the tray is not dropping then possibly the lift motor spring has come loose and the list motor is tilting forward as you pull out the tray and preventing the tray from dropping. The lift motor should be in the position shown in the photo, if you press on it, it should be slightly spring loaded and return to center when you stop pushing it. Make sure the tray lifts and drops properly when not in the printer.