Download
Share
Print this page
  1. Manuals
  2. Brands
  3. Frye Manuals
  4. Measuring Instruments
  5. FONIX FA10
  6. Maintenance manual

Frye Fonix FA-10 Maintenance Manual

Hide thumbs Also See for Fonix FA-10:

Advertisement

Quick Links

Download this manual
FONIX
®
FA-10
MAINTENANCE MANUAL
Revision 9
March 30, 2005
FRYE ELECTRONICS, INC.
P.O. Box 23391 • Tigard, OR 97281-3391
(503) 620-2722 • (800) 547-8209
Fax: (503) 639-0128
FRYE
www.frye.com • e-mail: sales@frye.com
Copyright ©2001 Frye Electronics, Inc.
All Rights Reserved

Advertisement

loading
Need help?

Need help?

Do you have a question about the Fonix FA-10 and is the answer not in the manual?

Questions and answers

Related Manuals for Frye Fonix FA-10

Summary of Contents for Frye Fonix FA-10

  • Page 1 ® FA-10 MAINTENANCE MANUAL Revision 9 March 30, 2005 FRYE ELECTRONICS, INC. P.O. Box 23391 • Tigard, OR 97281-3391 (503) 620-2722 • (800) 547-8209 Fax: (503) 639-0128 FRYE www.frye.com • e-mail: sales@frye.com Copyright ©2001 Frye Electronics, Inc. All Rights Reserved...
  • Page 2 CONTENTS 1. SERVICE AND REPAIR GUIDE ................1 1.1 Opening the FA-10 for Service ....................1 1.2 Separating Top and Bottom Half .................... 1 1.3 CPU/Keyboard Removal ......................2 1.4 CPU/Keyboard Installation ...................... 2 1.5 Auxiliary Keyboard Removal ....................2 1.6 Auxiliary Keyboard Installation Notes ..................
  • Page 3 2.2.12 Power On Reset ......................13 2.2.12.1 Introduction ....................13 2.2.12.2 Power On Reset Circuit Operation............14 2.3 CPU/Keyboard ......................... 15 2.3.1 Introduction ........................15 2.3.2 Master Clock ........................ 15 2.3.3 Watchdog Timer ......................17 2.3.3.1 Watchdog Timer Introduction ..............17 2.3.3.2 Watchdog Timer Circuit Operation ............
  • Page 4 2.7.5 Filter ..........................30 2.7.6 TONEON Switch......................30 2.7.7 VU LED Driver ......................31 2.7.8 VU LEDs ........................31 2.7.9 Power On LED ......................31 2.7.10 Mic Ref Supply ......................31 2.7.11 Left Mic Preamp Right Mic Preamp Talk Forward Amplifier Left External Buffer Right External Buffer ....................
  • Page 5 3.4 Procedure: Start ........................41 3.4.1 Enter Calibration Mode ..................... 41 3.4.2 Calibration ........................41 3.4.3 Alternate Earphone Calibration ................46 3.4.4 Exit Calibration Mode (and Store Calibration Data) .......... 46 3.5 Other Calibration Options ....................47 3.5.1 How to Discard Calibration Values ................. 47 3.5.2 To Enter Calibration Mode with Original Factory Calibration ......
  • Page 6 FA-10 HEARING EVALUATOR (220V) The following changes apply only to the 220V version of the FONIX FA-10: 1.11.1 Mains Supply Cord Delete the first sentence of this section. 1.11.3 Power Entry Module Change section to: The power entry module is Schurter type KD14.4101.107 2 pole snap-in for 2.0 mm panel thickness.
  • Page 7 1. SERVICE AND REPAIR GUIDE 1.1 Opening the FA-10 for Service 1. Remove the two screws on the FA-10 front plastic panel. 2. Remove the five screws on the FA-10 rear panel. 3. Gently lift the FA-10 front plastic panel. There is a hinge mechanism which allows the FA-10 case to be opened for servicing with all interconnect cables connected.
  • Page 8 2. Rotate the three knobs to a known position. 3. Remove the three knobs with a 0.050" (1.27mm) Allen (hexagon) wrench. Note the relationship between the flatted shaft tip and the knob index mark. The set FONIX FA-10 Maintenance Manual...
  • Page 9 screw will on the same side of the shaft as the flattened area on the shaft tip. You will need these positions during re-installation. 4. Remove the 1/2" hex nuts holding the rotary controls to the FA-10 front panel. The AUXILIARY KEYBOARD should fall free. 1.6 Auxiliary Keyboard Installation Notes 1.
  • Page 10 The FA-10 was designed as a 115 Volt only instrument and is equipped with a power entry module and a removable hospital grade mains supply cord. The mains supply cord should be replaced if it shows cracking or abrasion of the outer jacket. For FONIX FA-10 Maintenance Manual...
  • Page 11 safety, the mains supply cord should only be connected to a properly grounded mains power outlet. 1.11.2 Terminals The crimped on “quick disconnect” (spade lug) terminals have exact sizes and may be difficult for end users to obtain in small quantities. Important are: correct wire size, correct quick disconnect width, and correct quick disconnect mating thickness.
  • Page 12 Although the danger of spreading disease through the audiometric earphones is low, it is not non-existent. The manufacturer of the ear cushions recommends the use of any OSHA (Occupation Safety and Health Agency) recommended anti-bacterial soap. Disposable acoustically transparent covers are also available commercially. FONIX FA-10 Maintenance Manual...
  • Page 13 2. CIRCUIT DESCRIPTION 2.1 Introduction The FA-10 audiometer consists of 5 major circuit boards and two minor circuit boards. 2.1.1 Major Circuit Boards 2.1.1.1 Power Supply Board Converts AC power from the transformer to six DC voltages and generates power on reset. 2.1.1.2 CPU/Keyboard CPU/KEYBOARD controls the FA-10 via clocked serial I/O;...
  • Page 14 2.2.2 Power Transformer Transformer input voltage: 115 Volts AC. Transformer nominal output voltage: 14 Volts AC per winding, maximum load. The FA-10 Power transformer uses a split bobbin design which has two major advan- tages: FONIX FA-10 Maintenance Manual...
  • Page 15 1. Safety—the primary is isolated from the rest of the transformer by a very robust 4000 volt insulation system. 2. Radio frequency interference suppression—the stray capacitance between pri- mary and secondary windings is very small; a line input filter is not required. Necessary filtering is done at the transformer secondary circuit by the secondary side RFI filter.
  • Page 16 The current through R14 must be greater than 10mA, otherwise if the +11 volt power supply were operated without load, the LM350T output would rise above +11 volts towards the unregulated supply connected to the LM350T input. FONIX FA-10 Maintenance Manual...
  • Page 17 When operating, the LM350T will regulate its output so that it is Vref (=1.25V) above Vout. The voltage across R14 will be Vref. The voltage (referred to ground) at the ADJ pin is set by R11. Vadj = (R14 current + Iadj) x R11 Vout = Vadj + Vref FOR +11 VOLTS: Vout = (Vref x (1 + (R11/R14))) + (Iadj x R11) Vref = 1.25V typical...
  • Page 18 4 goes to -20 volts. The voltage on C2 adds to the voltage on J1 pin 4. The voltage at D2 cathode is -30 volts, C3 is charged to a voltage greater than the peak input volt- age. After a number of cycles, the voltage on C3 will equalize to about -40 volts. FONIX FA-10 Maintenance Manual...
  • Page 19 2.2.11 -22.3V Regulator Acceptable output range: -21.516V to -22.997V U1 is a TL431ACLP programmable shunt regulator. If pin 1 is positive by the amount Vref (about 2.495 volts) with respect to pin 2, then U1 will conduct current from pin 3 to pin 2. This current will increase rapidly as the voltage between U1 pins 1 and 2 increases.
  • Page 20 POR signal to chatter between “0” and “1”. U7F pin 12 switches to “1”, +5 volts. D5 is reverse biased so current through D5 goes to zero. R5 and R4 alone now form the U8 pin 1 voltage divider. The voltage FONIX FA-10 Maintenance Manual...
  • Page 21 divider formed by R4 and R5 will cause current to flow through U8 as long as C11 stays above Vtr-, about 14.3 volts. When U7F pin 12 switches positive, the signal is delayed about 20 to 50 microseconds by R13 and C15. This delay insures adequate time for the system microprocessor to reset.
  • Page 22 180º apart in timing. As long as the inverter has more gain than the loss in the crystal, the oscillator will oscillate. The availability of the full gain of the in- verter depends upon bypass capacitor C29. FONIX FA-10 Maintenance Manual...
  • Page 23 2.3.3 Watchdog Timer 2.3.3.1 Watchdog Timer Introduction If the CPU program goes out of control the Watchdog issues a logical “1” on signal DOG. DOG resets the Z80 CPU, resets parallel port outputs to logical “0”, and causes the patient audio outputs to silence. In addition, after the DOG signal clears to allow the Z80 CPU to restart, another signal, DOUBLEDOG, is issued which the Z80 CPU can examine to determine that the CPU has just recovered from a WATCHDOG RESET.
  • Page 24 • establishes the port address of the 8 bit parallel port, U19 • establishes the port address of the watchdog timer, U16 • resets the Watchdog Timer, U16, during power on reset. • establishes the port address of the UART, U23 FONIX FA-10 Maintenance Manual...
  • Page 25 RAM or read a byte from RAM. The RAM fits in the lower portion of the U18 socket. Socket pins 1,2,31,32 are empty. A jumper connects JP3 pins 2 and 3. The larger socket at U18 allows a larger RAM to be used by Frye Engineering for software development.
  • Page 26 FA-10 to restart, U8E pin 10 will be logical “0”. If U9 is not enabled then: pin 4 is open circuit; the watchdog status signal (inverted DOUBLEDOG) will pass through R30 unaffected and match U8E pin 10. FONIX FA-10 Maintenance Manual...
  • Page 27 2.3.9 Parallel Port U19, a 74HCT273, is an octal “D” flip flop with clear. Uf U19 pin 1 is set to logical “0” by signal SYSRES\, then all U19 outputs Q1..Q8 will be reset to logical “0”. The SYSRES\ feature prevents erratic FA-10 operation if the power supplies are under voltage.
  • Page 28 In order for a FrOut to operate, N>W and N>0. It is possible for the CPU to send either 1,2, or all 3 bytes to alter the contents of the CDP68HC68W1E: • pulse width alone may be sent, • frequency divide number and pulse width may be sent, FONIX FA-10 Maintenance Manual...
  • Page 29 • control, frequency divide number, and pulse width may be sent. For reliability, the FA-10 CPU always sends all 3 bytes. 2.3.12 Noise and Tone Generators U21 U21, SAA1099, is a stereo music synthesizer with 6 voices. The FA-10 uses only a small portion of the capabilities of this IC.
  • Page 30 U1, U2, U3, U4, and U5 into the CPU. U6 and U7 are double buffered so that data can be shifted into the IC without flashing the LEDs. Signal KEYSTROBE is held at logical “1” during the shifting process and then KEYSTROBE is returned to logical “0”. FONIX FA-10 Maintenance Manual...
  • Page 31 2.3.16 Push Button Switches These are simple single pole single throw normally open switches. 2.3.17 Rotary Encoder Switches These controls are rotary absolute gray code encoders. An encoder reports a unique (absolute) binary code for each encoder switch position. Between adjacent encoder switch positions, only one bit changes (gray code).
  • Page 32 • Filters square waves into sine waves (11 frequencies) • Filters logic level random noise into narrow band noise (11 frequencies) • Filters logic level random noise into speech weighted noise • Filters voice signals to simulate hearing aid slopes: 6dB 12dB 18dB HFE FONIX FA-10 Maintenance Manual...
  • Page 33 2.6.2 Filter Board Function Table U5, U20 FILTER AUDIOMETER MODE VU METER FILTER FILTER CLOCK, POLES INPUT SELECTED LINES SOURCE TYPE FREQ(s) C B A WHITE NOISE 0 0 0 INT REF NONE SPEECH NOISE 0 0 1 INT REF 115200 .957 1050...
  • Page 34 2.6.8 Output Anti-aliasing filter For most configurations, R40 and C5, a 19 KHz low pass filter is all that is required to round off the signal edges caused by the switched capacitor filter. For 125 Hz and FONIX FA-10 Maintenance Manual...
  • Page 35 250 Hz tones and noise, more filtering is required since the filter clock is at an audible frequency. The additional filtering is provided by the 470 Hz low pass filter at U8A. 2.6.9 +5A -5A U9 and U10 are 3 terminal linear regulators which convert ± 12 volt supplies to ± 5 volt supplies for use by the FILTER, OUTPUT, and VU METER BOARDS.
  • Page 36 2 is very near ground. When the front panel stimulus switch is pressed, the CPU issues signal L TONEON which causes U13B to switch to a voltage calculated to slightly exceed 0 VU; U13 pin 1 is at about 0.955 VDC typical. FONIX FA-10 Maintenance Manual...
  • Page 37 2.7.7 VU LED Driver U7 is a VU meter LED driver. U7 pin 7 reference voltage is 1.28 VDC typical. The current out of pin 7 sets LED segment current; LED segment current (10 mA) is about 10 times reference amplifier output current (1 mA). The reference amplifier output voltage sets the VU meter sensitivity for +3 VU.
  • Page 38 U1. The loudness of the response tone is preset and not adjustable by the operator. The response tone loudness is optimized for walkman style monitor headphones. 2.7.15 Patient Response LED Green, illuminated when the Patient Response switch is pressed. FONIX FA-10 Maintenance Manual...
  • Page 39 2.7.16 Talkback Microphone The talkback microphone preamp and and reference voltage supply are located on the OUTPUT BOARD. The talkback microphone preamp output, signal “TALKBACK”, is connected to pot R9. 2.8 Outbput Board (See OUTPUT BOARD schematics, 4 pages.) 2.8.1 Shift Registers U5 and U6 are serial input, parallel latched output shift registers.
  • Page 40 U16A is set for 40 dB of gain. U7B pin 9, signal “L ISRC MODE” when logicial “0” sets the bilateral current source for +40dB of gain. Level translator U8B pin 7 turns on JFET Q8 as part of the +40dB of gain. FONIX FA-10 Maintenance Manual...
  • Page 41 2.8.6 Digital Pots Attenuation steps less than 5 dB are provided by dual digital pot U12. U12 contains 2 strings of 255 equal value resistors. The output taps are selected by the 17 bit shift register contained in U12. The CPU uses U12 to provide attenuation steps of 0.1dB each.
  • Page 42 These are intended as external compact disk or as external cassette player inputs. The signals are fed through voltage followers to reduce the signal impedance and thus limit crosstalk from other FA-10 circuits. The buffered signals are connected to the VU METER BOARD. FONIX FA-10 Maintenance Manual...
  • Page 43 2.8.10.2 Talk Bac Mic J16 J16 is intended for connection to a Frye provided electret condenser micro- phone. The microphone is powered by U2A (+5 volts decoupled). The +5 volts decoupled is fed through R2, 10K to form a “long tail” current source.
  • Page 44 VU METER BOARD when the patient presses the patient response switch. The patient response logic level enables a CMOS switch on the VU METER BOARD which sums the patient response analog 1125 Hz tone into the monitor earphones circuit. FONIX FA-10 Maintenance Manual...
  • Page 45 3. CALIBRATION 3.1 Equipment Required a. A 1000 Hz sine wave generator (calibration not critical). b. A sound level meter*. c. An artificial mastoid with calibration table. If you are following this procedure for the first time and/or you have only a curve for your artificial mastoid, see appendix A.
  • Page 46 If the red LEDs flash, one or more of four conditions exists: • ALL THREE RED LEDs FLASH: The left Output switch set to Right Channel plus right Output switch set to Left Channel (part of switch combination used to enter and exit calibration). FONIX FA-10 Maintenance Manual...
  • Page 47 • ONE Hearing Level LED FLASHES plus FREQUENCY LED FLASHES: The Frequency setting for the output selected has been disabled by holding -2.5 dB until the calibration has reached zero output. • ONE Hearing Level LED flashes rapidly: You have exceeded the maximum output capabilities of the FA-10.
  • Page 48 • Disable the channel at calibration steps 16, 26, 31, 41, 61, and 71. Press and hold the Stimulus key and the -2.5 dB key until the Hearing Level LED flashes plus the Frequency LED flashes. This indicates that the channel is off. FONIX FA-10 Maintenance Manual...
  • Page 49 TABLE 1 Left Channel Earphone Calibration for TDH39 100Ω Earphones — — — For Eartone 3A Earphones (formerly ER3A), calibrate the same as for TDH39 Earphones, but use the following table. TABLE 1A Left Channel Earphone Calibration for Eartone 3A and 5A 50Ω Earphones —...
  • Page 50 — — — — — — — — — — — — — — — — — — — — — — — — — — — TABLE 3 Left Channel Speaker Calibration — — — FONIX FA-10 Maintenance Manual...
  • Page 51 TABLE 4 Right Channel Earphone Calibration for TDH39 100Ω Earphones — — — For Eartone 3A Earphones, calibrate the same as for TDH39 Earphones, but use the following table. TABLE 4A Right Channel Earphone Calibration for Eartone 3A and 5A 50Ω Earphones —...
  • Page 52 EEROM (electrically Erasable Read Only Memory) when leaving the calibration mode. Two copies of the data are stored in “field calibration tables”. This step may be performed at any point you choose during the calibration procedure. You may later resume where you left off. FONIX FA-10 Maintenance Manual...
  • Page 53 1. Set the left Input switch to Tone. 2. Set the right Input switch to Tone. 3. Set the right Output switch to Left Channel. 4. Set the left Output switch to Right Channel. 5. Set the left Hearing Aid Simulator switch to HFE. 6.
  • Page 54 2. Set the left and right Input switches to Tone. Set the right Output switch to Left Channel. Set the left Output switch to Right Channel. Set the left and right Hearing Aid Simulator switches to Off. FONIX FA-10 Maintenance Manual...
  • Page 55 3. Press and hold down all 4 of the following buttons: Output Reverse, Pulsed, Warble, Talk Forward. (Use a ruler or pencil.) 4. Turn the FA-10 rear panel POWER switch ON. At this point, the FA-10 is in calibration mode. Continue with all the calibration steps and then go to item 3.9 (following) to save the calibration data and exit calibration.
  • Page 56 Note: See Section 3.5.4 if you repalce the EEROM. 3.6.1 Field Calibration Table Bit Error Warning *, ** OR *** The Hearing Aid Simulator LEDs flash in a pattern of one, two, or three times in succession, with pauses between the grouping of flashes. FONIX FA-10 Maintenance Manual...
  • Page 57 This type of error can often be corrected by recalibrating the audiometer as de- scribed above, BUT DO NOT. Order a new EEROM from Frye Electronics, because the cost of this part is small compared to the usual cost of calibration.
  • Page 58 An inadvertent loss of calibration due to technician error can normally be cured by recalibrating the instrument. The EEROM can be calibrated over 10,000 times so that should not be a cause of concern. FONIX FA-10 Maintenance Manual...
  • Page 59 APPENDIX A Procedure to Establish Artificial Mastoid Calibration Table This procedure is to be done each time the artificial mastoid is sent to a certification laboratory. It is NOT done for each audiometer. Keep completed TABLE 6 in a safe place for reference.
  • Page 60 (nV, µV , mV, V). 9. Enter the appropriate values in TABLE 2. End of procedure Note: If you wish to calculate voltages 10 dB higher, multiply by the square root of √10 = 3.1623. FONIX FA-10 Maintenance Manual...
  • Page 61 TABLE 6 s t l Appendix A...
  • Page 62 APPENDIX B Conforms to ANSI S3.6-1996 and IEC 645-1 1992 Basis of Calibration Numbers Narrow Band Noise is calibrated for effective masking. White noise is calibrated in SPL. TABLE 7 Ω b i l The NBN calibration is based on the pure tone calibration for the selected fre- quency plus the correction recommended by ANSI S3.6-1996 Sect.
  • Page 63 1 kHz NBN is calibrated. The 12.5 dB used in Speech Noise and External Source is derived by adding 12.5 dB, the “crest factor” for voice from ANSI S3.6-1996 plus the correction factor for 1000 Hz tone. FONIX FA-10 Maintenance Manual...
  • Page 64 TABLE 9 Ω µ Notes: • Add correction factor for your artificial mastoid. • To obtain levels re 1 Dyne, subtract 20 dB from values given. • At 250 Hz the Bone Vibrator should be calibrated at 20 dB HL. •...
  • Page 65 1 kHz NBN is calibrated. The 12.5 dB used in Speech Noise and External Source is derived by adding 12.5 dB, the “crest factor” for voice from ANSI S3.6-1996 plus the correction factor for 1000 Hz tone. FONIX FA-10 Maintenance Manual...
  • Page 66 APPENDIX C LED Error Codes Which May Occur During FA-10 Operation Red LEDs The red LEDs on the front panel are used to indicate error conditions. There are three error LEDs. They have the following meanings: Operational Errors Problem: Left Level LED flashing at a 1/10 second rate: The left level is out of calibration.
  • Page 67 All LEDs (except power and response) flashing at a 1/10 second rate: Cause: System failure has occurred, LEDs are indicating the error number by the flash count. FONIX FA-10 Maintenance Manual...
  • Page 68 Cure: Turn the audiometer off then back on. If the problem does not go away, the audiometer is not operational and must be repaired by a qualified service technician. Problem: All LEDs (except response) are on continuously: Cause: While the power-on test sequence is being performed, all the front panel LEDs (except the response LED) will be turned on and left on until the test has been completed.
  • Page 69 Error Description Watch dog timeout error If the red LEDs flash continuously at a 1/10 second rate with no pauses, it is an indication of the following error: Flashes Error Description Uncorrectable system failure —cause unknown FONIX FA-10 Maintenance Manual...
  • Page 70 APPENDIX D Special Power-on Modes for the FA-10 Audiometer FA-10 Calibration: Normal Entry: Outputs to Other channel Inputs to Tone Hearing Aid Simulators to Off Press and hold Warble and Pulse while turning on the audiometer Enter with Restored Factory Calibration: Outputs to Other channel Inputs to Tone Hearing Aid Simulators to Off...
  • Page 71 = 1; 9 flashes = 9; no flashes = 0 FA-10 Easter Egg: Set Inputs to Tone Set Hearing Aid Simulators to Off (Output selection is not important) Press and hold both –2.5 dB and both Stimulus buttons while turning the FA-10 power on. FONIX FA-10 Maintenance Manual...
  • Page 72 APPENDIX E Rear Panel Safety Markings CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH 1/2 AMP SLOW 250 V FUSE Never replace a fuse with a fuse which has a rating higher than specified. The fuses are 0.5A 250V 3AG Slow Fuses must have at least one safety approval mark.