Hi @badlarry ,
What assembly do you mean?
Looking at the image (click on image to enlarge) in the guide for the power button board, there appears to be only the button and a LED on the board unless other components are on the other side of the board of course.
The board number for the power button board is RM1-8711. The supplier in the link is shown only to give an idea of the cost. There are others that may suit you better. Just search for RM1-8711 to get results.
If you mean the assembly where the power button board connects to, find the board number and then search online using the board number only to hopefully find suppliers.
Here’s a link to the parts catalogue for the printer. It may help a bit as it shows all the parts but unfortunately not all the part numbers, only selected ones.
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
2