Help testing TR and SP boards

HI, Ive got an HD11Xe that has thrown the instrument error code. Ive tested the TR boards but putting them in the 1 and 2 slot and starting the machine. I had one bad board. Then I found that a good board in the number 3 slot will cause the same error but putting the good board in the number 4 slot works with no error. However the HD11 fails to generate an image through either probe. One probe appears that its working but doesn't actually resolve an image and the other is completely blank. I suspect the SP board and one TR board is bad. I don't have any manuals for this machine so I'm kind of stabbing in the dark. Any help is appreciated.