Table Of Contents - Teac A-400 Service Manual

GENERAL INTRODUCTION
This Service Manual is compiled to assist service technicians by
providing procedures and corrective measures for adjustment, care
and maintenance, and the ordering procedures for needed parts.
lf adjustments or repairs are too complicated and are difficult for
you to accomplish, or if you have any technical questions, please
contact the nearest TEAC Factory. Service Department or write
: directly to a TEAC office, the addresses of which are written on the
back cover.
NOTE
When ordering replacement parts, please refer to the PARTS
* "Dolby" and the Double D
symbol "OQ" are trademarks of
Dolby Laboratories Inc. The
Noise reduction circuit is made
under license from Dolby Labo-
ratories Inc.
LIST which is printed separately from this manual.
CONTENTS
1. Specifications & Service Data ............2 0.000: 3 4. Electrical Checks and Adjustments .........+5--55 13
2. Partial Dis-assembly of Main Parts ................ 4 General Notice ........ 0.000 ee BB
Test Equipment Required... ..----+++ 13
2-1. Cabinet Removal .............-204 4
2-2.
Front Panel Removal ...........0e08
4 4-1
Monitor Performance
.......-+++000- 14
2-3. Cassette Holder Removal ............. 5 : 4-1-1. Specified Input Level Setting .......+--- 14
2-4,
Tape Transport Chassis Removal .........
5
4-1-2. . Minimum Input Level Checks .....-----> 14
2-5.
Head Replacement
............. Poeee
4-1-3. Level Meter Calibration
.....0--25
eee 14
2-5A.
Record/Playback Head... ........000-
6 4-1-4.
Peak Level Indicator Setting
....--.----- 15
2-5B.
EraseHead .......0.00
cc cc eaeees 6
4-1-5.
Headphone Output Level Checks
.....--> .15
2-6. Pinch Roller Replacement ............. 6 4-2. Playback Performance .....----+ 0-0 es 15
2-7. Reel Table Replacement ............. 7 4-2-1. Record/Playback Head Azimuth
2-7A, Take-up Reel Table... ..........-04- 7 SMIUSIGIG 9:02. 2-g 0 ah e h series sep ens 15
278. Supply Reel Table
.................
j
4-2-2. Specified Output Level Setting
...--- es 16
2-8. Motor Replacement..........-...00.
7 4-2-3.
Level Meter Indication Checks...
+--+ +s 16
2-9. Flywheel/Capstan Belt Replacement ....... 8 oe Playback Frequency Response Checks ..... ss
2-10. Fast Wind Idler Replacement ........... 8 SScests © SHGNGL A TEDIRE A BG CRERIS sana elete SACS S
4-3, Record Performance: .......-+-++055 17
Parts Location ......... 0.0000 eee 4 4-3-1. Bias Trap Adjustments .......--+-ee0005 17
4-3-2. Bias Adjustments for '1' Position
3. Mechanical Checks and Adjustments ............... 3 (CrO. Tape)... 6... ee ee ee eee V7
4-3-3. Bias Adjustments for 2" Position
Test Equipment Required .............
9
(Regular Tape)
.........-- s t g A aden ake 17
4-3-4. Record Level Setting .....-- 2+ - ee eee 18
3-1. Pinch Roller Pressure ...........-44- 9 4-3-5, Distortion Checks ....... 2-020 eee 18
3-2. Take-up Torque Measurement........... 10. 4-3-6. Overall Frequency Response .-----++:-> 18
3-3. Fast Forward Torque Measurement ....... 10 4-8-7. Overall Signal-to-Noise Ratio... .--. eee 19
3-4. Rewind Torque Measurement ........... 1 4-3-8. Erase Efficiency... .....-0 002 ee eee 19
Torque Measurement using the Cassette
4-3-9.
Channel Separation . S i l aces
eae ees 20
Torque Meter .....2.......000. a 4-3-10. ~ Crosstalk between Adjacent Tracks .-.---- 20
4-3-11. Dolby *NR System Efficiency Checks ...... 20
"3-5. Tape Speed Adjustment/Wow and Flutter 4-4, Adjustment & Test Point Location ......-.- 21
Measurement... 20... 0... cee eee eee 11 :
3-6. Solenoid Position Adjustment. .......... 12
5. Level Diagram .....-.0.0-c
eee ee eee ees 22
3-7. Muting Switch Position Adjustment ....... 12
3-8.
Voltage Selector Setting Procedure
....... 12 G: Troubie-dhootttits.eoeeed
we ee ea ee ee 23
3-9. AC Power Line Frequency Adaptation..... . 12
3-10. Lubrication 2.2.0 ...0........20005 12