Aspect Medical Systems BISPECTRAL INDEX A-2000, Service Manual

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SECTION VII DISASSEMBLING AND REASSEMBLING THE A-2000™
- 7-11 -
7.5
THE PRINTED CIRCUIT BOARD ASSEMBLY
The Interconnect PCB and connected assemblies must be removed to gain access to the
Main PCB, fan, battery, power supply, or rear case shell.
7.5.1
Removing the Printed Circuit Board assembly
1. With rear case assembly dismounted from bezel (see Section 7.2.1), place rear case
assembly face down on a scratch free work surface with bottom of case facing you.
(See Figure 7-7).
2. From bottom surface remove right side rubber foot, steel flat head screw (center),
and nylon flat head screw (right side).
3. From monitor rear surface remove ground stud (use 7/16 driver wrench), two screws
from AC input module, and two screws from deep recess holes.
4. Carefully stand case upright, being careful to not damage cable attaching fan (case
mounted) to Interconnect PCB. (See Figure 7-8).
5. Disconnect fan cable from Interconnect PCB. (Pry release tab away from connector.)
Case is now free from the Printed Circuit Board Assembly. Be careful to not lose two
case screws (in deep recess) or power switch cap.
6. Printed Circuit Board Assembly or rear case shell are now ready for further service
activities.
7.5.2
Installing the Printed Circuit Board Assembly
Refer to Figures 7-7, 7-8 and 7-21.
Note:
On newer A-2000 units copper tape has been added to the inside of the
monitor case to improve the ground connection. The tape improves the
conductivity between the L bracket of the Interconnect PCB and the
shielded coating of the inside of the case. If your unit does not have the
tape, it is recommended that you install it as shown in Figure 7-21.
1. With the rear case sitting upright on its bottom surface, connect the fan cable to the
J30 Interconnect PCB connector (next to the battery). (See Figure 7-8).
2. If power switch cap has been removed, install it with the 0 on the button facing the
rear of the instrument.
WARNING:
DUE TO THE BATTERY OPERATION POSSIBLE WITH NO AC CONNECTED,
EXTREME CARE MUST BE USED WHEN DISASSEMBLING AND
ASSEMBLING THE A-2000 MONITOR. WITH AC DISCONNECTED AND
BATTERY POWER ON, HIGH VOLTAGE IS PRESENT ON THE E/L DISPLAY
AND POWER SUPPLY PCB. DO NOT ACTIVATE POWER ON SWITCH WITH
CASE OPEN!
3. Place the Printed Circuit Board Assembly carefully inside the case and hold against
back wall.
4. Install equipotential stud into rear case. Do not tighten.
5. Install the two screws into the deep recesses in rear case. Do not tighten.