Hologic DISCOVERY A, Technical Manual

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Discovery QDR Series Technical Manual
5-36
Figure 5-19
Trigger on CH1
Figure 5-20
Trigger on CH2
11. If timing is out of specification, (no steady LOC LED) loosen the two encoder
board mounting screws, and adjust the PCB up or down to get timing in specifi-
cations. When timing is in specifications, retighten the PCB mounting screws
and recheck timing. If necessary, readjust the timing. The LOC LED must be
solid on and steady.
12. Replace the Aperture Assembly.
5.9.2 Drum Belts
To remove and replace either Drum Belt (130 teeth or 150 teeth), refer to Figure 5-18 and
follow the procedure below:
1. Push the Emergency Stop button.
2. Remove the Aperture Assembly by removing 4 Phillips screws that secure the
assembly, and 2 Phillips screws that secure the aperture motor mount, to the drum
end plates (refer to Figure 5-16).
500
μ
s
Segment
Signal
Jigger
Brass
Signal
500
μ
s
Jigger
Segment
Signal
Brass
Signal