Welch Allyn Micro Tymp 2 User manual

4341 State Street Road
P.O.Box 220
Skaneateles Falls, NY 13153-0220
Copyright 1995
MicroTymp 2
Tympanometric System
23640 handle, 71170 printer charger
(Includes CE Model)
Service Manual
Part #:236409

Part Rev Desc. of Change ECN # Date Initiator
236409 B New Release 5-28225 6/95 R. Settembre
236409 C Added CE Updates & Cautions 5-35489 6/97 R. Settembre
NOTE: Drawings & illustrations in this document are for reference only. Consult system
or call factory for latest revisions.
MICROTYMP 2

SERVICE MANUAL
MicroTymp 2
Tympanometric System
23640 handle, 71170 printer charger
(Includes CE Model)
Copyright 1995
Welch Allyn Co.
4341 State Street Road Welch Allyn
P.O. Box 220
Skaneateles Falls, NY 13153-0220 Service Manual Part #:236409

FORWARD
This manual provides technical assistance for calibrating, diagnosing, and servic-
ing the Welch Allyn MICROTYMP 2 handle and Printer/Charger.
The MicroTymp 2 and or Printer Charger will be returned to the Technical Ser-
vice Department for either Recalibration (handle only) or for diagnosis and repair. For
Printer Charger tests, refer to current factory approved diagnostic tests. Once the fault
has been determined, refer to the Manual chapters I and J for the appropriate Removal
and Replacement sequence. Re-test the Printer Charger after the repair is completed.
Similarly, when servicing the MicroTymp 2 handle, refer to the most recent troubleshoot-
ing guide and Calvin Users guide. Once the failed component has been identified, refer
to the Manual chapters B through H for the appropriate Removal and Replacement
sequence. Re-test (re-calibrate) the handle once the repair has been completed.
The repair ‘TASK’ procedures (R & R .. Removal and Replacement) are written
to provide quick and easy reference for different experience levels of repair technician.
Required specifications and materials are listed at each step where applicable. For
example:
Instructions will start off with a “TASK, TO DO.” For example, B. 3. “Unplug Flex
Circuit” statement. This will be followed by a “TECHNIQUE, HOW TO DO” statement.
Follow these steps to preform the task.— “Grasp pump assembly flex circuit with pin
straightening pliers.”
This manual is written in a style useful for training and or translation. Set up
training sessions to allow the trainee to practice the use of the diagnostic, repair, adjust-
ment, and re-testing procedures found in this manual. Set up hands-on practice ses-
sions to enable the technician to develop and retain skills. Provide each trainee with the
opportunity to practice the procedure(s) after it has been demonstrated by the instructor.
I M P O R T A N T :
Welch Allyn service part numbers and material numbers appearing in this manual are
for the purpose of familiarizing new technicians with the Welch Allyn parts numbering
system. Order replacement parts, as always, by referencing your latest bill of materials,
parts catalog and assembly drawings. Part number changes, product updates, or new
test procedures should be noted on the appropriate page of this manual by the manual
owner.
i

*** SAFE SERVICE ***
CLEAN AND DISINFECT per instructions in MicroTymp2 Operating Instructions PN
236311 PAGE C-50 prior to repairing, or calibrating all returned MicroTymp 2’s.
PERFORM appropriate “A” tests after servicing to assure safe, accurate and reliable
product operation.
*** QUALITY SERVICE ***
WEAR an ESD wrist strap when servicing the MicroTymp 2 or handling printed circuit
boards.
STORE new and used boards in anti-static bags.
UPDATE your Repair & Training Manual by notating changes and revisions of part
numbers and procedures.
READ AND UNDERSTAND customer comments and complaints on accompanying
documentation (P.O. or other correspondence).
If an injury, illness to patient or user, or hazardous malfunction has occurred or is sus-
pected, PROCEED NO FURTHER ! DO NOT disassemble, repair, adjust, or in any way
alter the MicroTymp 2 or the printer charger base ... instead, notify your supervisor at
once. Give them all accompanying paperwork and any information you might have on
the return. They will take appropriate action according to Welch Allyn policy. Check
customer service records to determine if this MicroTymp 2 requires or has received any
applicable retrofit modifications, improvements, or inspections, and perform these if
required.
INSPECT AND TEST it before and after it is repaired. Documentation should include:
general condition, defects, missing components and labels, electrical, functional and
mechanical problems. Operate the returned instrument to try to duplicate the
customer’s complaint before and after it is repaired.
ii

TABLE OF CONTENTS / MICRO TYMP 2
Forward - - - - - - - - - i
Safe Service - - - - - - - - - ii
Section 1
Removal and replacement ( r & r ):
A Normal maintenance - - - - - - - - - 1
B Power supply board assembly - - - - - - - - - 2
C Motor/pump assembly - - - - - - - - - 3
D MCU Board assembly - - - - - - - - - 3 - 4
E Keypad assembly - - - - - - - - - 4 - 5
F LCD Assembly - - - - - - - - - 5
G ESD Shields - - - - - - - - - 6
H Valve - - - - - - - - - 7
I Ballast - - - - - - - - - 7
J Printer / charger keypad - - - - - - - - - 8
K Printer and or PCB - - - - - - - - - 8 - 10
Section 2 Preliminary Handle Bench Test
Section 3 Micro Tymp 2 Noise Test Procedure
Section 4 Technical Troubleshooting Guide for Micro Tymp 2 Handles & Printer Chargers
Section 5 Customer Service Questions/Answers
Section 6 CALVIN, Micro Tymp 2 Calibration System User Manual
Section 7 Micro Tymp 2 NEEDS CAL Error Troubleshooting Guide
Section 8 Tools/Test Equipment listing Calvin Components
Section 9 Repair Parts
Section 10 Drawings
Section 11 A-02727 Process Sheet excerpts for 23641 Micro Tymp 2 Handle tests
Section 12 A-02728 Process Sheet excerpts for 71171, 71172, 71174, 71176, 71179
Micro Tymp 2 Printer Charger Tests

ANORMAL MAINTENANCE : BATTERY COVER, BATTERY, RECHARGING
BATTERY, RECYCLING THE USED BATTERY
A 1. REFER TO PAGE C-43 THROUGH C-47 OF MICROTYMP 2 OPERATING
INSTRUCTIONS FOR REPLACEMENT OF BATTERY PN72900.
WARNING: INSERT BATTERY ONLY AS SHOWN IN THE OWNERS
MANUAL. FAILURE TO OBSERVE CORRECT POLARITY COULD CAUSE
DAMAGE TO THE MICRO TYMP 2. WHEN IT IS NECESSARY TO RE-
PLACE THE BATTERY, USE ONLY A WELCH ALLYN PN72900 REPLACE-
MENT BATTERY. OTHER NON APPROVED BATTERIES MAY CAUSE
RISK OF FIRE OR PRODUCT FAILURE.
CAUTION:The battery must be removed if the MicroTymp 2 is to be stored
or placed anywhere other than in the Charging Stand (or connected to the
Charging Transformer) for more than one month.Failure to do this can
result in damage to BOTH the battery and the MicroTymp 2.
A 2. FOLLOW THIS PROCEDURE FOR DECIDING WHEN TO REPLACE THE NI-
CAD BATTERY IN A MICRO TYMP HANDLE: (AS ALWAYS, READ THE
CUSTOMER COMPLAINT FIRST.)
SCENARIO 1 If the unit FUNCTIONS, (the battery has held sufficient charge during
approximately two days transit) the battery meets requirements. No
corrective action is to be taken. However, it is good practice to put the
battery on charge for however long it is in your possession.
OR
SCENARIO 2 a If the unit DOES NOT FUNCTION AND the battery is IN warranty, put in
a fully charged new battery (your test battery). If the unit functions, and
Low Battery symbol disappears, REPLACE THE BATTERY UNDER
WARRANTY. Install a fully charged BATTERY. Recycle the failed battery
per Welch Allyn’s recycling policy.
2 b If the unit DOES NOT FUNCTION AND the battery is OUT of warranty,
put in a fully charged new battery (your test battery). If the unit functions,
sell a new battery. If the unit does not function, look for other problems
while charging the customer’s battery. Sell a new battery if customer’s
battery won’t ACCEPT AND HOLD a full charge.
NOTES:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
1

NOTE: WEAR ESD WRIST STRAP WHILE PERFORMING THE FOLLOWING OPERATIONS.
BPOWER SUPPLY BOARD ( TOP BOARD ) ASSEMBLY
B1.REMOVE BATTERY COVER.
FOLLOW INSTRUCTIONS IN MICROTYMP 2 OPERATING INSTRUCTIONS
TO REMOVE BATTERY COVER AND BATTERY. IT IS NOT NECESSARY
TO REMOVE THE FRONT HOUSING ASSEMBLY FOR POWER SUPPLY
BOARD REPLACEMENT.
B2.DISCONNECT TUBING FROM TOP BOARD.
REMOVE TUBING FROM MOTOR/PUMP ASSEMBLY.
REMOVE TUBE FROM BALLAST.
B3.UNPLUG FLEX CIRCUIT.
GRASP PUMP ASSEMBLY FLEX CIRCUIT WITH PIN STRAIGHTENING
PLIERS. PULL STRAIGHT UP TO REMOVE FLEX CIRCUIT FROM THE
POWER SUPPLY BOARD.
B4.REMOVE POWER SUPPLY BOARD.
UNSCREW 4 PHILLIPS HEAD SCREWS AT THE FOUR CORNERS OF `
THE POWER SUPPLY BOARD. LIFT THE CONTACTS FROM THE CASE
AND LIFT POWER SUPPLY BOARD STRAIGHT UP.
REPLACE POWER SUPPLY BOARD
B4.REPLACE POWER SUPPLY BOARD.
ATTACH TUBING TO THE PUMP AND THE BALLAST. REFER TO TUBING
ROUTING DIAGRAM ON DRAWING 236300. ALIGN BOARD OVER STAND-
OFFS WITH BATTERY HOLDER NEAR THE BOTTOM OF THE HANDLE.
SCREW THE BOARD TO THE STRAIN RELIEFS WITH TWO LONG
SCREWS AT THE BOTTOM OF THE BOARD, AND TWO SHORT SCREWS
AT THE TOP OF THE BOARD.
B5.PLUG IN FLEX CIRCUIT.
PLUG FLEX CIRCUIT INTO BOARD USING PIN STRAIGHTENING PLIERS
OR FINGERS. IF THE TWO FIBER SEPARATORS BECOME LOOSE, RE-
CONNECT THEM IN THEIR ORIGINAL POSITION (REFER TO ASSEMBLY
DRAWING) WITH LOCTITE BLACK MAX ADHESIVE M-30341.
B6.CALIBRATE HANDLE WITH CALVIN.
REFER TO SECTION 6 FOR CALVIN PROCEDURE. UPON SUCCESS-
FUL CALIBRATION AND TEST, PLACE A DROP OF BLACK MAX tm
ADHESIVE M-30341 BETWEEN THE FRONT HOUSING AND THE FIBER
STRIPS. REPLACE BATTERY AND BATTERY COVER.
SCREW BATTERY COVER IN PLACE.
END POWER SUPPLY BOARD REPLACEMENT
NOTES:________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
2

CMOTOR/PUMP ASSEMBLY
C1.REMOVE BATTERY COVER AND BATTERY.
UNSCREW BATTERY COVER SCREW AND REMOVE THE COVER.
REMOVE THE BATTERY FROM THE BATTERY HOLDER.
C2.REMOVE FRONT HOUSING ASSEMBLY.
PEEL THE WELCH ALLYN LABEL FROM THE UNIT AND UNSCREW TWO
SCREWS UNDER THE LABEL. REMOVE THE FRONT HOUSING ASSEMBLY
FROM THE HANDLE. DO NOT UNPLUG FLEX CIRCUIT FROM LCD BOARD.
NOTE: If unit is a CE model, take caution in removing the front housing.
There are two pieces of fragile ESD tape at both corners.
C3.REMOVE TUBING FROM MOTOR/PUMP ASSEMBLY.
PULL TUBE FROM THE PUMP. PULL TUBE FROM THE BALLAST.
DISCONNECT FLEX CIRCUIT FROM SWITCHES BOARD AND POWER
SUPPLY BOARD. GENTLY LIFT MOTOR/PUMP ASSEMBLY UP.
REPLACE MOTOR PUMP ASSEMBLY
C4.REPLACE MOTOR/PUMP ASSEMBLY.
INSTALL REPLACEMENT PRE/ADJUSTED MOTOR/PUMP ASSEMBLY
OVER LCD RETAINER. RE-ATTACH FLEX CIRCUITS TO POWER BOARD
AND SWITCH BOARD. USE PIN STRAIGHTENING PLIERS OR FINGERS
TO RE-ATTACH FLEX CIRCUITS. RE ATTACH FRONT HOUSING ASSEM-
BLY. LAY FLEX CIRCUITS IN ACCORDING TO DRAWING #236300.
C5.CALIBRATE HANDLE WITH CALVIN.
REFER TO SECTION 6 FOR CALVIN PROCEDURE. UPON SUCCESSFUL
CALIBRATION AND TEST, PLACE A DROP OF BLACK MAX tm ADHESIVE
M-30341 BETWEEN THE FRONT HOUSING AND THE FIBER STRIPS.
REPLACE BATTERY AND BATTERY COVER. SCREW BATTERY COVER
IN PLACE.
NOTES:________________________________________________________________________
______________________________________________________________________________
DMCU ( BOTTOM ) BOARD
D1.REMOVE POWER SUPPLY BOARD ( TOP BOARD ).
FOLLOW INSTRUCTIONS IN SECTION B FOR REMOVAL OF POWER
SUPPLY BOARD.
D2.UNPLUG FLEX CIRCUIT FROM MCU BOARD ( BOTTOM BOARD ).
USE PIN STRAIGHTENING PLIERS OR FINGERS TO GENTLY PULL THE
FLEX CIRCUIT FROM THE MCU BOARD SOCKET.
D3.REMOVE MCU BOARD.
UNSCREW FOUR STANDOFFS WITH 1/8" NUT DRIVER. GENTLY PULL
THE BOARD STRAIGHT OUT OF THE HOUSING. FOUR PLASTIC
SPACERS ARE ATTACHED TO THE BOARD AT EACH SCREW HOLE.
TRANSFER THESE TO THE REPLACEMENT MCU BOARD.
3

DMCU ( BOTTOM ) BOARD
D4.REPLACE MCU BOARD.
INSTALL FOUR PLASTIC SPACERS ON THE BOTTOM OF THE BOARD.
INSERT REPLACEMENT BOARD INTO HANDLE WITH INFRA-RED LED AT
BASE OF HANDLE FACING IR WINDOW. SCREW FOUR STANDOFFS
INTO CORNERS OF MCU BOARD. TIGHTEN TO 1.5 TO 2 INCH LBS.
D5.PLUG IN FLEX CIRCUIT.
CONNECT THE FLEX CIRCUIT TO THE MCU BOARD SOCKET. INSERT
SIDE CONTACTS INTO THE SLOTS OF THE BACK HOUSING WITH THE
BLACK WIRE ON THE RIGHT (BALLAST) SIDE, AND THE RED WIRE ON
THE LEFT SIDE. TUCK CONTACT WIRES UP AGAINST BOTTOM END OF
BATTERY RETAINER.
D6.INSTALL POWER SUPPLY BOARD.
FOLLOW INSTRUCTIONS IN SECTION B FOR REPLACEMENT OF
POWER SUPPLY BOARD. CALIBRATE UNIT USING CALVIN SYSTEM
(CALVIN USERS MANUAL IN SECTION 6)
NOTES:________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
EKEYPAD ASSEMBLY
E1.REMOVE FRONT HOUSING ASSEMBLY.
FOLLOW INSTRUCTIONS IN SECTION C2 TO REMOVE FRONT HOUS-
ING.
E2.REMOVE MOTOR/PUMP ASSEMBLY.
FOLLOW INSTRUCTIONS IN SECTION C3 TO REMOVE MOTOR/PUMP
ASSEMBLY.
E3.REMOVE LCD MODULE SUPPORT FROM BACK HOUSING.
UNSCREW TWO SCREWS AND LIFT SUPPORT DOWN AND AWAY FROM
LCD MODULE. DO NOT ALLOW THE LCD DISPLAY TO FALL OUT OF
THE BACK HOUSING. PRESS ANY BUTTON TO LIFT KEYPAD ASSEM-
BLY OUT OF BACK HOUSING.
REPLACE KEYPAD ASSEMBLY
E4.REPLACE KEYPAD ASSEMBLY.
INSERT REPLACEMENT KEYPAD ASSEMBLY INTO HOLES IN BACK
HOUSING WITH LETTERS RIGHT SIDE ‘UP’. ALIGN LCD RETAINER
OVER LCD AND KEYPAD ASSEMBLY AND INSERT LATCH OF RETAINER
INTO NOTCH IN TOP OF BACK HOUSING. ALIGN 2 ALIGNMENT PINS ON
THE BACK OF THE RETAINER WITH THE TWO ALIGNMENT HOLES IN
THE KEYPAD ASSEMBLY PRINTED CIRCUIT BOARD. SECURE RE-
TAINER WITH TWO SCREWS.4