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Sony EA-80 Service Manual

Educational amplifier


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1st Edition


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Summary of Contents for Sony EA-80

  • Page 2 The material contained in this manual consists of only. information that is the property of Sony Corporation and is To reduce the risk of electric shock, fire or injury, do not intended solely for use by the purchasers of the equipment perform any servicing other than that contained in the described in this manual.
  • Page 3: Table Of Contents

    2-4-2. Switch, Indicators, Audio and Communication Circuit Check by an Oscilloscope .................. 2-4 2-4-3. Indicators, Audio and Communication Circuits Check by EA-80 Connected to LLC-8000 ..........2-4 2-5. NOTES ON REPAIR PARTS ................ 2-5 2-5-1. Notes on Repair Parts ................2-5 2-5-2.
  • Page 4 SECTION 1 OPERATING INSTRUCTIONS This section is extracted from page 1-14 in LLC-8000 operation manual. (part number : 3-858-846-13) Operating the EA-80 Educational Amplifier Make copies of this page and hand out a copy to each student, if necessary. Signing in Press ATTENDANCE when instructed to do so by your instructor.
  • Page 5: Service Overview

    When installing the cover, put the harness in the notch of the AU-254 board so that the cover does not catch the harness. Cover AU-254 Board Notch 1 SW-952 BOARD : Switch & CPU 2 AU-254 BOARD : Audio Harness EA-80...
  • Page 6: Connector Specification

    +15V INCOM -10 dB Input 0 dB = 0.775 Vrms *1: Connecting a power supply to EA-80, short pin 1 of CN1 to pin 2 of CN1. Power EA-80 Supply +15 V *2: The level of the signal supplied from AUX L IN or AUX R IN is -16 dB.
  • Page 7: Performance Check Mode

    4. Keep pressing the switch SW6 on on the SW-952 board, that is, the ATTENDANCE/CALL button until completing step 5 below. 5. Three seconds later, all response indicators (D1 through D6 on the SW-952 board) flash. 6. Release the SW1, SW3, SW5 and SW6. EA-80...
  • Page 8: Indicators, Audio And Communication Circuits

    When the communication is established, the indicator D6 on the SW-952 board) flash. that shows the student unit, EA-80, being checked and 5. Disconnect the pin 4 of CN1 on the AU-254 board located at the left-above the monitor button on the from GND of the power supply.
  • Page 9: Notes On Repair Parts

    : Less than 2 seconds per pin Replacement of ICs 1. Using the braided wire, “SOLDER TAUL” (Sony Part No. 7-641-300-81), remove the solder around the pins of the IC-chip to be removed. 2. While heating up the pins, remove the pins one by one using sharp-pointed tweezers.
  • Page 10: Spare Parts

    Therefore, specified parts should be used in the case of replacement. (2) Standardization of Parts Repair parts supplied from Sony Parts Center may not be always identical with the parts which actually in use due to “accommodating the improved parts and/or engineering changes”...
  • Page 11: Exploded View

    3-165-013-11 o KEY (S), TOP 3-747-922-21 s KNOB 4-937-336-32 o HOLDER, LED (h=4 mm) *for D1 through D5 4-937-336-91 o HOLDER, LED (h=6 mm) *for D6 8-719-064-85 s DIODE TLOU114 8-759-495-61 o IC TMP90PH-EA80V100 PTP3x8 PTP3x8 PS 3x6 PS 3x6 EA-80...
  • Page 12: Electrical Parts List

    1-216-081-00 s METAL, CHIP 22k 5% 1/10W 1-216-073-00 s METAL, CHIP 10k 5% 1/10W 1-216-049-91 s METAL, CHIP 1k 5% 1/10W 1-216-033-00 s METAL, CHIP 220 5% 1/10W 1-216-101-00 s METAL, CHIP 150k 5% 1/10W 1-216-093-00 s METAL, CHIP 68k 5% 1/10W EA-80...
  • Page 13: Supplied Accessories

    1-216-083-00 s METAL, CHIP 27k 5% 1/10W 1-241-358-11 s RES, ADJ, CARBON 20k 1-572-404-11 s SWITCH, PUSH 1-572-404-11 s SWITCH, PUSH 1-572-404-11 s SWITCH, PUSH 1-572-404-11 s SWITCH, PUSH 1-572-404-11 s SWITCH, PUSH 1-572-404-11 s SWITCH, PUSH 1-579-929-11 s RESONATOR, CERAMIC 9.8300MHz EA-80...
  • Page 14: Semiconductor Pin Assignments

    _5 to _12V +5 to +22.5V _5 to _22.5V M5219/M5220 TYPES +2.5 to +18V _2.5 to _18V MC33077DR2 NJM2100 TYPE +1 to +3.5V _1 to _3.5V OP-297 TYPE +2 to +20V _2 to _20V OTHERS +5 to +16V _5 to _16V EA-80...
  • Page 15 P10 - P17/ PORT A0 - A7 (512 B) 32 - 39 P20 - P27/ PORT TIMER A8 - A15 WAIT P37/ /TO1 8-BIT 2CH (TIMER 0/1) PROM (16 KB) TIMER PORT P35/ 8-BIT 2CH P81/INT1/TI2 P36/ (TIMER 2/3) EA-80...
  • Page 16 In case EA-80 sends data “0” The EA-80 turns the voltage at the pin 3 of the CPU(IC1) on the SW-952 board to 0 V. When the voltage at the pin 3 of the CPU is 0 V, the parts, R13, 17 and 18 on the SW-952 board, and also Ra and Rb on the LLC-8000, turn the voltage at the D.SIG terminal(pin 4 of CN1) on the AU-254 board to 0.5 V.
  • Page 17 SW-952 SECTION 6 BOARD LAYOUTS AND SCHEMATIC DIAGRAM * : B SIDE CNI1 SW-952 -A SIDE- 1-667-870-11,12 SW-952 -B SIDE- 1-667-870-11,12 EA-80...
  • Page 18 ATND/CALL 1.8k No.1 2.2k No.2 2.2k No.3 2.2k No.4 2.2k No.5 2.2k 9.83MHz 220k CL202 CL201 C104 470p 220k 7.5V C109 C108 470p 470p IC3(1/2) NJM4560M-TE2 HEAD PHONE AMP(R) 220k 7.5V 220k IC3(2/2) C105 NJM4560M-TE2 470p HEAD PHONE AMP(L) EA-80...
  • Page 19 IC2(1/2) NJM4560M-TE2 MIX AMP CL31 CL32 CL34 CL35 R101 R102 AUX L IN AUX R IN A.GND PGM OUT MIC OUT C106 C107 470p 470p A.GND 150k 150k 150k 150k Suffix-11 Suffix-12 C100-109 470P R101,102 1/2W AU-254 SW-952 B-EA80-SERVICE EA-80...
  • Page 20 AU-254 EA-80 (SY) : S/N 50001 and higher * : B SIDE *IC1 *IC2 *IC3 AU-254 -A SIDE- 1-667-869-12 AU-254 -B SIDE- 1-667-869-12 EA-80...
  • Page 21 AU-254 EA-80 (E) : S/N 40001 through 41500 * : B SIDE *IC1 *IC2 *IC3 AU-254 -A SIDE- 1-667-869-11 AU-254 -B SIDE- 1-667-869-11 EA-80...
  • Page 22 Printed in Japan Sony Corporation 1997. 11 04 EA-80 (E, SY) 9-955-136-01 Image & Sound Communication Company ©1997 Published by Engineering Services Dept.

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