I know this is an old thread but wanted to share a note.

SP3450H
My problem was 814 @ power up. MRC1 was not powering up & ED2 not closing. Had already checked off the two 814 steps in the book. OK

MRC1 was not getting B+ at CA402-14. This comes from CA212-8 (no B+ @ CA212-8 either). Following the dist board diag this power comes from the bank of caps bott right center of board.

Luckily I have an old dist board with other issues to swap in for test. Problem resolved!

-Yes, K2 was checked
-Yes, All Connections/plugs were checked.

Confirmed by reinst. orig board and problem returned.

Update: Uppon inspection of old dist board I found the solder point of the large coil (bottom center) next to CR7 had broke. For whatever reason this board DID NOT have the white silicone on the coil and caps like most current dist boards have now. I re-soldered the landing point and tested the board. No fail! :)