JRC JMR-92 Series Field Service Manual page 331

Step 4 Replace the modulator circuit board.
Remove the cables connected to the modulator circuit board, then remove the screws (five M4
screws) holding it in place and the spacer (one 7 mm (nominal) spacer), and then replace it.
If reusing the heat radiation plate on the modulator, be sure to install the insulation sheet
between the TR5-8 and the heat radiation plate so that it is straight. After having replaced the
modulator circuit board, reassemble the unit following the disassembly procedure in the reverse
order. Do not forget to tighten the screws and connect the cables.
Step 5 Operation check
After having completed the replacement, turn On the safety switch and check operation by
following the procedure below.
(1) Turn On the Display unit. After the countdown is completed, start transmission and check
that the radar image appears without error.
Emit the radio wave in long pulse range mode and open the service engineer menu to
check that the magnetron current stands between the 5th and 7th calibration markings.
This completes modulator circuit board replacement.
Remove the spacer.
Disconnect the five cables.
4-111
Remove the five
screws.
Chapter 4 Replacement procedure