Teac A-400 - Table of Contents

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 eh 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)
.........--
stg
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
.
Sil
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