wherein said step of installing said circuit board includes {TAIL ~ a step} of mounting {HEAD ~ said circuit board} on said rear tray 
wherein said step of installing said circuit board includes { TAIL ~ a step } of mounting { HEAD ~ said circuit board } on said rear tray
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH