Paper Jam caution will not clear M452dN

[OliverPluff]

The Paper Jam caution will not clear.  The screen caution says there is a "Jam in the paper path. Open read door and clear the jam".  I have opended the rear door and repeatedly checked that there is no jammed paper present (both steps 1 and 2).  I have turned off and unplugged the machine.  I have loaded plain white letter size paper in tray 2.  Still the caution comes on after I turn the machine back on. How do I reset the caution so I can use my printer

[WillySTL]

We are an MSP and I've replaced three of this exact model, this month.  One was fuser, other two are reporting jams like this.  Now I'm worried about the others we have in field.  Could be a fluke, but never seen issues crop up like they have with these printers recently.  All about 2 years old when issues came up. 

[Repairatrooper]

I had a unit with similar issue. It turned out to be a jammed flag in the pickup assembly. Easiest way to check is to remove the cartridges, remove the paper tray and then place the printer on one side so that  you can see all the pickup assembly inside the paper tray cavity. 

[Chrisftw13]

Repairatrooper,

Rear door paper jam

I've taken my HP M452 apart multiple times, saw your post and did everything (removed paper tray, removed all the cartridges and put it on it's side with the rear door open).

Can't find any paper jam, I looked at the 3 pages that came out before the jam to see if there was any small pcs missing, none

Anyway to "reset" the printer to clear it  ?

Many thanks and best regards,

Chris