Service manual

PN 4237242C
2.3-8
INSTRUMENT DESCRIPTION
FLUIDICS PANEL
Lyse Pump (PM5)
The lyse pump (Figure 2.3-1) is a solenoid pump with a spring return. Several specifications
of this pump should be considered when troubleshooting the lyse system. It has an adjustable
working range of 200 to 450 µL and should be set to 415 ±5 µL. It cannot be energized for
more than 6 seconds or damage will result. The MD II energizes the lyse pump for 300 ms
whenever it dispenses lyse and has a fail-safe that cuts power after 1 second.
Internal sealing is accomplished using both O-rings and diaphragms. To leak back to the lyse
container, reverse pressure would have to pull through a spring pressured O-ring seal and a
diaphragm seal, similar in action, to a check valve. Forward pressure opens the diaphragm
seal by design, just as forward pressure causes flow through a check valve. Forward pressure
would also push against the spring, weakening the O-ring seal. For this reason, the pump is
rated at only 6 in. of positive pressure meaning the lyse container cannot be greater than 6 in.
above the pump.
Solenoid Interconnect Card
The Solenoid Interconnect card is located in the lower chassis (Figure 2.2-2) and provides an
interface for wiring the Diluter Panel solenoids and the horizontal probe position sensors in a
convenient location.
To facilitate servicing the instrument, LEDs were added to each solenoid line. A lit LED
indicates that its associated solenoid is being energized by the system. See Table 2.3-4 for
connector and LED associations.
Table 2.3-4 Solenoid Interconnect Card Connectors and LEDs
Connector Solenoid or Sensor LED
J1 LV6 CR1
J2 LV7 CR2
J3 LV11 CR3
J4 LV10 CR4
J5 LV3 CR5
J6 LV13 CR6
J7 LV4 CR7
J8 LV14 CR8
J9 LV8 CR9
J10 LV16 CR10
J11 LV5 CR11
J12 LV15 CR12
J13 LV2 (on Vacuum Sensor card) CR13
J14 LV1 (on Vacuum Sensor card) CR14
J15 S1 (WHT position) No LED
J16 S2 (RED position) No LED
J17 S3 (ASP position) No LED
J18 Spare No LED
J19 Out to Motor/Solenoid Driver card No LED