MFC-5720DW Phantom Jamb at power on

[NeoMatrix]

Brother MFC-5720DW has random phantom jamb from power on or every 2nd or 3rd sheet out of the tray.

The machine has low copy count with only 2700 copies.
Displays reads "1: Jamb at front".

Check paper path(s) for possible paper scraps, all seems ok.
Have execute user Maintenance "remove paper scrap mode."

Checked encoder strip for damage, all appears ok.

Suggestions welcome before I pull the machine down.

Tnx Neo

[Elmtech]

Possible comtamination on the encoder carriage movement or paper feed. Also possibly paper width sensor on the carriage PCB.

[NeoMatrix]

Possible comtamination on the encoder carriage movement or paper feed. Also possibly paper width sensor on the carriage PCB.

This model is a pain to get simple access to any sensors.
Where is the paper width sensor you're referring too ?
Is that sensor up under the print head carriage ?

I'll have strip all the covers off this machine,oh joy...

[Elmtech]

Yeah thats the one underneath the carriage pcb. They can be a pain in the ass and tbh i have never had that sensor fail on that model.