Fan; Prescaler Options - Fluke PM6690 Service Manual

– Pull the interior unit out of the cover.
C
Figure 3-5
Remove the screws and pull out the main
PCB.
Reinstalling the Cover
– Push the counter gently back into the cover.
– Turn it upside down
– Fit the two screws at the bottom.
– Fit the two rear feet with their screws to the rear panel.
– Fit the four decorative plugs.
Figure 3-4
The fan is fixed with four screws and nuts. The 3 GHz & 8 GHz prescalers are fixed with snap-in clips. The OCXO is sol-
dered to the main board.
4 screws to remove

Fan

– Disconnect the power cable.
– Remove the cover from the counter. See page 3-2.
– Remove the four screws, nuts and washers that fix the
fan to the rear panel.
– Disconnect the fan power supply connector from the
main PCB and remove the fan.
– When reinstalling the fan, make sure the air-flow arrow
on the fan points to the rear of the counter and the black
wire is oriented toward the rear panel.

Prescaler Options

– Disconnect the power cable.
– Remove the cover from the counter. See page 3-2.
– Disconnect the cable from the mini-coax connector on
the RF input.
– Press the clips apart and lift the RF input PCA straight
up and out.
– When installing the RF input, make sure the connector
pins fit exactly in the holes of the connector housing.
Disassembly, Fan 3-3