001-303 problem lower left hand door interlock switch 7335

[tech9]

Hello fellow techs, this seems to be an issue on these 73xx machines where if you open and close the lower door the message does not disappear from the control panel.
The switch is ok and is being actuated by the door correctly. the tray pwb has been changed but for some reason the machine locks up saying to close the door.
Only popo will correct ? Any ideas.
thanks

[tech9]

Faulty interface pwb replaced that all okay