printing on wrong side

[ltipton]

I can print just fine from tray 1 on the correct side of the check with the check loaded face up/top first.  HOWEVER from tray 2 - even using the instructions to turn off 2-sided printing and load checks with top side last in tray 2 - THE CHECKS PRINT ON THE WRONG SIDE.  HELP PLEASE.

[dansdaduk]

Some printer models support an option known as Alternative Letterhead Mode .

With this enabled, this allows 'sided' paper (such as Letterhead) to be loaded in the cassette trays in the same way for both Simplex and Duplex jobs (so that you don't have to reload the paper if successive jobs use different plex modes).

The way it works is that for Simplex jobs, the printer generates a dummy rear face, and passes the paper through the duplex unit (the downside is that simplex throughput is reduced).

With my LaserJet Pro 400 Colour MFP M475dn, the option can (theoretically) be changed via an option on the Advanced tab of the Printing Preferences dialogue:

I've no idea whether or not this is relevant to your LaserJet M402dn model though.