500 sheet tray for HP LaserJet Pro 400 M401 - Not Recognized

[Ingomarguy]

Here's what happens when there is paper loaded in both Tray 2 & Tray 3 and the printer is configured to pick from Tray 3:

1. hitting "print", the printer displays "Load Tray 3 (plain/letter) or press [OK] to use available media.
2. I hit OK, and it prints from Tray 2 instead.

If there is paper only in Tray 3, but none in Tray 2, then the printer simply displays "Load Paper"

Bottom line = I still can't get it to print from paper loaded in Tray 3.

[DeoptINTLTech]

With the printer at "Ready", open tray 3, make sure the rear guide is set to Letter and reinsert the tray. Does the control panel show what tray 3 is set to? If not, enter the menus and scroll to System Setup Menu, first choice is Language, second choice is Paper Setup. Make sure tray 3 is set to Plain Letter.

[Ingomarguy]

All settings exactly as you described.  But, the problem as I originally presented it still exists:  won't print from Tray 3.

[DeoptINTLTech]

Can you scan the first page on the Configuration report and upload it?

[Ingomarguy]

Thanks, DepotINTL!   Here you go....

[DeoptINTLTech]

When you print a configuration page, does it ask to load plain paper or does it print without asking anything?

Cant you change "any type" to "Plain" and change "any size" to "Letter"?

[Ingomarguy]

Configuration Report prints out from Tray 2 without any additional prompts.

Have now altered the configuration so that Tray 3 Size: Letter and Tray 3 Type: Plain (as confirmed by a new Configuration printout.  STILL telling me to load paper in Tray 3, then defaults to Tray 2.  

[DeoptINTLTech]

When you open Tray 3, does the control panel say Tray 3 is open? If it does, when you close it does the control panel state what is loaded in Tray 3?

Besides doing a factory reset I am out of ideas. Unfortunately I do not have an M401 to check anything else. I am going by any other HP printer I have worked on. If tray 3 is set to plain letter and you print a config page, it will pull from tray 3 first and it didnt in your case. If you want to try a factory reset..

Restore the factory-set defaults (touchscreen control panel)
1. From the Home screen on the product control panel, touch the Setup  button.
2. Scroll to and touch the Service menu.
3. Scroll to and touch the Restore Default sbutton, and then touch the OKbutton.
The product automatically restarts.

Mind you this will reset your lan, but it will also set the paper trays to default, which should be plain letter except for tray 1.

[Ingomarguy]

If I open tray 2 the control panel switches to "load paper"; when I close it, the display reverts to "ready"

If I open & close tray 3, the display never leaves "ready"

Will now try the Factory Reset....

[DeoptINTLTech]

Alright...pull out tray 2 and look inside the printer, do you see a sensor flag hanging down? Now open up tray 3 and look for a similar flag. Flag might be stuck and not detecting paper.