GSI 18 Service Manual Rev F

GSI 18 Audiometer

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Table of contents General service information ... 1-1 CMOS handling precautions ... 1-1

1 - Product Specifications Catalog listings ... 1-3 Standards and Compliance ... 1-3 GSI 18 Specifications ... 1-4

2 - Functional Description Functional theory of operation ... 2-3 Keypad ... 2-3 Encoders... 2-3 Serial EEPROM... 2-3 JTAG... 2-3 RS232... 2-3 Power supply... 2-4 Power source selection... 2-4 Sleep mode... 2-4 GSI 18 Hardware diagram... 2-5 General operation of controls ... 2-6 Rear panel connectors... 2-7 Table of symbols on the GSI 18... 2-8 Bottom panel... 2-8

Controls and indicators ...2-9 LCD display ...2-11 Power options... 2-13 Connecting the AC power... 2-13 Disconnecting the AC power... 2-13 Battery operation... 2-13 Sleep mode... 2-13 Low battery indicator... 2-13 Replacing the batteries... 2-14 Removing batteries ... 2-14 Placing new batteries ... 2-15

3 - Routine Maintenance Routine maintenance ... 3-3 Earphone cords ... 3-3 Hum and random noise ... 3-3 Distortion and frequency shift ... 3-3 Special messages... 3-3

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4 - Calibration Calibration... 4-3 Equipment required... 4-3 GSI 18 quick reference calibration procedure ... 4-3 Verifying the calibration ... 4-4

Calibration mode ... 4-5 Transducer calibration mode... 4-6 Custom RETSPL Value mode... 4-6 Gain calibration mode... 4-7 Diagnostic mode ... 4-8 Equipment required... 4-8 Hardware Diagnostic Submode ... 4-8 Pushbutton Diagnostic Mode... 4-9 Display Diagnostic Mode ... 4-12 ADC Diagnostic Submode... 4-14 Max Output Calibration ... 4-15

5 - Disassembly Disassembly ... 5-3

6 - Appendix Appendix A - Error codes. ... ...6-3 Appendix B - GSI 18 service parts ... 6-4

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D-0004810 Rev F

General Information

General Service Information Operating, check-out procedures, troubleshooting hints, etc., can be found in the User Manual. Repair and/or bench testing of GSI 18 Audiometers should only be performed by trained personnel. The following instructions are provided primarily for use by persons who are skilled in the repair of electronic equipment.

CMOS handling precautions Many of the integrated circuits on the P.C. boards are CMOS and NMOS type.

Failure to observe the following precautions whenever a circuit board or an integrated-circuit package is handled can result in damage to the GSI 18. a. Place instrument and parts on a grounded, conductive work surface. b. Ground yourself (with a strap having approximately 1 Mohm resistance). c. Ground the frame of any test instrument or soldering iron to be used. d. If any circuit boards are to be stored or transported, enclose them in conductive (antistatic) envelopes.

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GSI 18 Audiometer

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Product Specifications

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GSI 18 Audiometer

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Product Specifications

Catalog listings GSI 18 Screening Audiometer, HB7 headband

8515213

GSI 18 Screening Audiometer, HBA headband

8515220

Standards The GSI 18 meets: ANSI S3.6

Specification for Audiometers (Type 4)

IEC 60645-1

Electroacoustics - Audiological Equipment - Pure Tone Audiometers (Type 4) It is Class 1, internally powered with Type B applied parts.

IEC 60601-1

Medical Electrical Equipment Part 1 - General Requirements for Safety

UL 60601

Medical Electrical Equipment, Part 1 -General Requirements for Safety

CAN/CSA-C22.2 No. 601.1-M90

Medical Electrical Equipment - Part 1: General Requirements for Safety

IEC/EN 60601-1-2

Medical Electrical Equipment Part 1 - Electromagnetic compatibility requirements

Compliance The CE 0123 mark identifies compliance with the Medical Device Directive 93/42/EEC. Grason-Stadler is an ISO 13485 certified corporation. 0123

European Authority Representative Grason-Stadler c/o DGS Diagnostics A/S Audiometer Alle 1 5500 Middelfart Denmark

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GSI 18 Audiometer

GSI 18 Specifications Frequency Range Discrete Frequencies:

125, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, 6000, 8000 Hz

Accuracy:

±2%

Total Harmonic Distortion: <2.5% measured acoustically at the maximum Hz for frequencies below 5000 Hz and measured electrically above 5000 Hz.

Intensity TDH-39 Headphones

DD45 Headphones

125 Hz -10 to 50 dB HL 500 to 6000 Hz -10 to 90 dB HL 250 and 8000 Hz -10 to 70 dB HL

125 Hz -10 to 50 dB HL 500 to 4000 Hz -10 to 90 dB HL 6000 Hz -10 to 85 dB HL 250 and 8000 Hz -10 to 70 dB HL

NOTE: The maximum output values in dB HL are reduced by 10 dB when insert phones (EAR 3A/5A) are used, except for 6 kHz where the maximum dB HL is reduced by 20 dB.

NOTE: A “+10” dB button extends the maximum at all frequencies by 10 dB. Accuracy:

125 to 4000 Hz, ±3 dB 6000 to 8000 Hz, ±5 dB

Signal to Noise Ratio:

>70 dB

Tone Type Rise/Fall Time:

20-50 msec

Continuous:

Steady when present bar depressed

Pulsed:

2.5 pulse/sec

FM:

±5%, 5 Hz, Triangular modulation

Head set DD45 Earphones (10 ohm) with Type 51 Cushions (10 ohm impedance). Headband

Exerts a force between 4 and 5 N when the earphones are separated by 145mm.

Power

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Input Voltage:

The AC-DC adapter is a universal auto-ranging with an input voltage range of 100-240VAC at 50 - 60 Hz.

Consumption:

1.5 Watts

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Product Specifications

Battery Types:

5 each: Alkaline AA 1.5V 5 each: Rechargeable NiCad or NIMH AA 1.2V. NOTE: The instrument does not provide a recharging circuit for these batteries.

Capacity:

Minimum of 10 hours of power for either battery type. A Low Battery of power.

icon will display when there is approximately 1 hour left

Environmental Temperature Operating:

59° F to 104° F (15° C to 40° C) NOTE: Longer warm-up time is required if storage temperature is different from room temperature.

Ambient Pressure:

98 kPa to 104 kPa

Warm-up Time:

10 minutes for instruments stored at room temperature

Storage/Shipping:

-93° F to 149° F (-34° C to 65° C)

Battery Storage:

-4° F to 105° F (-20° C to 40° C)

Humidity:

15% to 95%

Mechanical Dimensions:

12.59” W x 8.76” D x 3.18” H (32 cm W x 22.3 cm D x 8.1 cm H)

Weight

2.55 lbs (1.16 Kg) with 5 AA batteries

Supplied Accessories

Catalog Numbers

Headset, 10 ohm (DD45)

8010954

Audiogram Forms (1 pad of 50)

8012941

GSI Manuals USB

8504319

Bag, Carrying

8004664

AC Power Supply

8511988

GSI 18 Quick Guide

8029312

Threshold Audiometry Card

8011933

Optional Accessories Response Handswitch

8004365

Patch Cord, 2 conductor

8004383

Audiocups

8010855

Insert Phone Assembly 3A (10 ohm impedance)

8103001

Insert Phone Assembly 5A (50 ohm impedance)

8010921

! WARNING Use only Grason Stadler supplied components and accessories. D-0004810 Rev F

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Functional Description

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GSI 18 Audiometer

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Functional Description

Functional theory of operation The GSI 18 is an audiometric screening product offering basic pure tone audiometry. The system is built around an NXP ARM7 processor. The user interface consists of a custom segment LCD, an 8-button membrane keypad, and two rotary encoders. The device provides two audio jacks for connection to a headset or insert phones used for audiometry. A patient Response switch can be connected to a third audio jack. A 6-pin modular phone jack is provided to connect to the GSI Auto Calibrator and to provide a port for software upgrade. The audio tones are generated by a Direct Digital Synthesizer (DDS), which is controlled by the processor over an SPI port. A 10-bit DAC provides gain control for the audio outputs. The DAC’s are also controlled over an SPI port.

Keypad

Encoders Serial EEPROM

JTAG RS232

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The user interface has 8 buttons implemented in a membrane keypad. The keypad has selections for extended range, right or left ear selection, tone type selection, and transducer selection. Each button has its own IO line that will be shorted to ground when the button is pressed. An ESD diode, ferrite bead, capacitor, and pull-up resistor are placed on each of the eight keypad signal lines. The keypad does not contain an LED to indicate power on since this is accomplished by the LCD. A separate elastomeric button is used for the Present switch. When this button is pressed, the present signal will be shorted to ground. An ESD diode, capacitor, series resistor, and pull-up resistor are placed on the present signal. The hearing level is controlled by 2-bit rotary encoder. The frequency selection is controlled by a 4bit rotary encoder. The encoder signals have ESD diodes, ferrite beads, and pull-up resistors. A serial EEPROM with an I2C interface is used to store calibration data. Only the A2 address line is used on the 8kbit device, and this pin is pulled high to give the device an address as shown below where PI and P0 are the page address and R/W is high for reads and low for writes. The LPC213x processors provide a JTAG port for debug and code loading. The JTAG port is connected to a 20 pin header which is not accessible from outside of the enclosure. The processor’s serial port 0 is connected to a 6-pin modular jack to allow for connection to the GSI Auto Calibrator. The RXD, TXD, DTR, and RTS signals are provided to the connector, and they are at TTL levels. The RS232 connector is accessible from the rear panel; however, it is covered by a label. The RS232 port can also be used to load new software. General purpose IO port P0.14 must be held low during reset to enable the processor’s in system programming mode. The host RS232 RTS signal is used to toggle the P0.14 line, and the DTR signal is used to reset the board. An external RS232 transceiver will be needed to level shift the TXD, RXD, DTR, and RTS signals. The Softbaugh BRS232 is an off-the-shelf RS232 transceiver module that can be used.

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Power supply

The GSI 18 is powered by an AC-DC adapter with a single 7V output or from batteries. The adapter has an IEC320-C14 compliant input connector and a 2.1mm output plug. The GSI 18 will accept five AA cell batteries. The GSI 18 does not provide circuitry to charge the batteries. The circuitry has been designed to accommodate the following battery chemistries: Alkaline with a nominal voltage of 1.5V per cell Nickel Cadmium with a nominal voltage of 1.4V per cell Nickel Metal Hydride with a nominal voltage of 1.4V per cell

Power source selection Sleep mode

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Power on will be indicated by activating the LCD. The AC/DC POWER signal will be at a logic high level when the AC/DC adapter is connected to the unit. If the power source is the AC/DC adapter, the AC PWR icon will be displayed on the LCD. The Sleep mode is entered when the unit is being run on batteries and the sleep mode timer expires. Every key press on the front panel or remote command will reset the sleep timer. If it is not reset for 5 minutes, the unit will enter sleep mode. The tone generator is put in sleep mode, all normal interrupts are disabled, and the Present button is reprogrammed to be the external interrupt that wakes up the processor. The display is cleared except that four dashes ‘----‘ are displayed in the frequency digits. The processor is then put in the Sleep mode. Pressing the Present button or cycling the power exits sleep mode. If the Present button is pressed, the unit returns to the same state it was in when the Sleep mode was initiated. Pressing the Present button to exit sleep mode does not turn on the stimulus.

8012134 Rev. 5

Functional Description

GSI 18 Hardware diagram

Figure 1 - GSI 18 hardwire diagram

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GSI 18 Audiometer

General operation of controls Rear Panel Connectors R1

R2

R3

R4

R5

R6

R1 – For Service Use Only. R2 – Patient Hand Switch Input Jack (standard phone jack). R3 – Right Earphone output jacks (standard phone jack). Insert either DD45 Headphone or Insert Earphone jacks. R4 – Left earphone output jacks (standard phone jack). Insert either DD45 Headphones or Insert Earphone jacks. R5 – Power Input jack (2.1mm pin) R6 – Power Switch

WARNING Do not turn on/off system power while a patient is wearing the headsets or insert earphones. Use only the GSI provided power supply. The GSI 18 provided power supply should only be connected to a power source meeting the following range: 100- 240VAC, 50-60Hz. In North America, the power source should be a maximum of 120VAC.

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Table of symbols on the GSI 18

Symbol

Description

Conforms to European Medical Device Directive 93/42/EEC.

Symbol for "SERIAL NUMBER."

GSI Part Number.

Return to Authorized Representative, Special disposal required.

Medical Equipment Classified by Intertek Testing Services NA Inc. with respect to electric shock, fire, and mechanical hazards only, in accordance with UL 60601-1. Classified under the Medical Device Directive (93/42/EEC) as a Class IIa device.

Symbol for “European Representative.”

Symbol for “Manufacturer.”

Symbol for “Date of Manufacture.”

China RoHS symbol for products with a 50 year life cycle.

Patient applied part Type B according to IEC 60601-1

Alkaline (1.5V) or Rechargable (1.2V), NiCd or NiMH

AUD

The Left respective Right transducer of the headset is connected to this output for Audiometry measurements.

Consult Operating Instructions.

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Follow Instructions for Use.

Keep Dry

This side up

Fragile – handle with care

Bottom Panel

B1

B2

B1 – Label location includes serial number of the system B2 – Battery Compartment NOTE: See Replacing the Batteries Section for detailed instructions

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