Welch Allyn 220 Installation instructions

Disassembly and Repair Section 4
Service Manual 6200-43E Rev. DWelch Allyn Atlas Monitor 63
About Section 4
This section is a guide for disassembly and reassembly of the Atlas Monitor. Always refer to
current revision schematics, diagrams and final safety test procedures before attempting to
service this device.
Do not attempt to service this instrument unless you have received Service Training from
Welch Allyn or an authorized Training Agent, and are equipped with approved processes
and test equipment. For more information about training call the Welch Allyn Customer
Service phone number listed in Section 1 of this manual.
General:
The outside housing is removable in order to provide full access to all internal printed cir-
cuit boards and other components. Most of these are held in position with the surrounding
“E-Pac” foam. E-Pac foam provides shock absorption, ventilation channels, and spaces for
the components and boards. Pneumatic tubing and cables must be placed correctly in E-Pac
to avoid problems with pinched tubing.
Problems During Service:
A Technical Support phone number is listed in Section 1 of this manual to answer questions
you may have during the servicing of the Atlas Monitor.
Printer:
Print-head, printer motor, and printer roller can be replaced as necessary.
Printed Circuit Boards:
There are no component level repairs for the Printed Circuit Boards(PCB). These are
replaced if found to be defective. During the warranty period, boards that are found to be
defective should be returned to Welch Allyn.
EXERCISE EXTREME CAUTION WHEN
SERVICING THE ATLAS MONITOR! THE
CRT ASSEMBLY AND CRT DEFLECTION
BOARD OPERATE ON APPROXIMATELY
8,000 VOLTS.
CRT:
The CRT and CRT Deflection Board are aligned at the factory and as such are replaced as a
matched set if one or the other should fail in service.
Electrical Shock Hazard
CAUTION

Section 4 Disassembly and Repair
64 Welch Allyn Atlas Monitor Service Manual 6200-43E Rev. D
ESD: Circuit Boards are
sensitive to static electric-
ity. Use wrist straps, ESD
mats and ESD storage
bags.
1. Battery Door Removal
Remove the two screws holding the bat-
tery door. Remove the battery door.
2. Battery Removal
Remove the battery connector from the
main PCB. Remove battery.
Model 220 (623NP)

Disassembly and Repair Section 4
Service Manual 6200-43E Rev. DWelch Allyn Atlas Monitor 65
3. Rear Housing Removal
3.1 Remove the four Torx head machine
screws. Use a #10 Torx driver.
3.2 Pull the rear housing away from the
front panel. Take special care not to dam-
age any cables.
3.3 Flip the housing forward. Take special
care not to damage any cables.

Section 4 Disassembly and Repair
66 Welch Allyn Atlas Monitor Service Manual 6200-43E Rev. D
NOTE: Observe how hose fits in E-Pac
Foam. The hose fits over wiring keeping
wiring secure.
4. Printer cable and Display Cable
Removal
Remove both Printer and Display PCB
cables from the Main PCB.
5. Power Supply Ground Wire
Removal
Remove the two ground connectors from
power supply chassis.
Printer
Cable
Display
PCB Cable

Disassembly and Repair Section 4
Service Manual 6200-43E Rev. DWelch Allyn Atlas Monitor 67
6. Tie Wrap Removal
Cut the tie wrap that secures the ground
wires to the E-pac foam.
7. CPU Removal
Remove the CPU from the Main PCB.
8. Main PCB Removal
Use a tool T-16654 to pry the main Board
away from the Deflection Board. Pull the
E-pac tab to the right as you pry. Support
the Main PCB while titling it away.

Section 4 Disassembly and Repair
68 Welch Allyn Atlas Monitor Service Manual 6200-43E Rev. D
9. Main PCB Side Connector Removal.
Remove the four connectors(power sup-
ply, fan, speakers, BP pump) from the side
of the main PCB.
10. Main PCB Hose and Wire
Removal.
Disconnect hoses and connectors. BP
hose, ecg cable, temp cable (modles 622
and 623 only, SpO2cable, CO2cable
(model 623 only)and ground wire (Nelcor
SpO2only) from main PCB.
NOTE: Notice how hoses and connectors
fit on Main PCB.
11. Pump Removal.
Remove the pump assembly from the E-
Pac foam.
NOTE: Notice how pump fits in E-Pac
Foam and how wires are routed out of
pump.

Disassembly and Repair Section 4
Service Manual 6200-43E Rev. DWelch Allyn Atlas Monitor 69
12. CO2Exhaust Removal.
Remove the CO2exhaust cover and
remove the CO2 connector from the E-Pac
foam.
13. Pryon PCB Removal.
Remove connectors from Pryon PCB. Pull
Pryon PCB from E-Pac foam.
14. E-Pac Foam Removal (Top).
Remove the top E-Pac foam.

Section 4 Disassembly and Repair
70 Welch Allyn Atlas Monitor Service Manual 6200-43E Rev. D
15. Power Supply Removal.
Slide the power supply out from the E-Pac
Foam.
16. Power Supply Fuse Location
NOTE: Notice power supply and power
supply fuse location.
17. Fan Removal
Slide fan out from E-Pac foam.
Fuse

Disassembly and Repair Section 4
Service Manual 6200-43E Rev. DWelch Allyn Atlas Monitor 71
18. E-Pac Removal (Lower)
Remove lower E-Pac foam from unit.
19. Deflection PCB Removal
Carefully remove the small deflection PCB
from the CRT.
20. CRT Removal
Remove the two machine screws holding
CRT to the front panel.
NOTE: Notice how the ground wire is
attached and is located along the side of
CRT.

Section 4 Disassembly and Repair
72 Welch Allyn Atlas Monitor Service Manual 6200-43E Rev. D
NOTE: The CRT and deflection PCB are
factory tuned as a unit and are sold only
together as a unit.
21. Display PCB Removal
Remove all 9 self tapping screws that hold
the Display PCB to the Bezel.
NOTE: Notice the correct orientation of
CRT screw and washer.