[TenTec] Paragon 585

[ROLAND HOWELL]

Good Evening gents from the UK
Having another attempt to repair my 585 Paragon, the dreaded 'PLL out of Lock' message on the display.
So far I have managed to confirm that the 42mHz is there, doubled to 84mhz and divided to the 2.1mhz on the REF/OSC board, incidentally it has a different pcb board number than the one in the manual, a later/uprated board?.
On the PLL board the 4 x VFO,s switch as they should do, active VFO is low compared to the others.
Have ordered the 3 x legged fuses and IC,s so that I have them to hand when I get to completing more tests.
I have checked for the usual dry joints on the boards, minor, major loops and ref/osc
oh nearly forgot I am not sure if I have a 2.7mHz - 2.75mHz input from the minor loop board, I think its output is so low it is not recording on my 9916 frequency counter. 
Now is there any advice that you learned gents can offer, I don't want to start changing ic,s and trannies on the off chance that 1 of them is faulty.    
Thanks
Snowy G0HZE