Operating instructions

4.2.8.2 Fast Cue Mode (Lifter Defeat) .............................. 4-8
4.2.9 Spot Erasure ..................................................... 4-9
4.2.10 Variable Speed Mode ............................................ 4-9
4.2.11 External Speed Reference ...................................... 4-10
4.3 Auto Locator Operation .......................................... 4-10
4.3.1 Entering Locate Times .......................................... 4-10
4.3.2 Storing Cue Points .............................................. 4-11
4.3.3 Recalling Cue Points ............................................ 4-11
4.3.4 Clearing Cue Points ............................................. 4-12
4.3.5 Search .......................................................... 4-12
4.3.6 Search Zero .................................................... 4-13
4.3.7 Shuttle ......................................................... 4-14
4.3.8 Auto Rewind .................................................... 4-14
4.3.9 Setting the Tape Time Readout (Offset Mode) .................... 4-15
4.3.10 Zero Set ....................................................... 4-15
4.3.11 Stop Watch .................................................... 4-15
Section 5 Maintenance
5.1 Demagnetizing and Cleaning ..................................... 5-2
5.1.1 Demagnetizing the Heads and Tape Guidance Path ................ 5-2
5.1.2 Cleaning the Tape Path ........................................... 5-3
5.1.3 Cleaning the Head Shield Screw .................................. 5-4
5.2 Routine Maintenance .............................................. 5-5
5.2.1 Removing and Reinserting the Printed Circuit Boards .............. 5-5
5.2.2 Hour Meter ...................................................... 5-5
5.2.3 Reel Motor Replacement ......................................... 5-6
5.2.4 Brake Pad Replacement .......................................... 5-7
5.2.5 VU Meter Lamp Replacement ..................................... 5-8
5.2.6 Head Shield Position Adjustment ................................. 5-8
5.3 Circuit Descriptions ................................................ 5-9
5.3.1 Playback Head and Preamp ....................................... 5-9
5.3.2 Speed Selection and High Frequency Playback Equalization ........ 5-9
5.3.3 Low Frequency Playback Equalization ............................. 5-9
5.3.4 Sync Playback ................................................... 5-9
5.3.5 Output Stage ................................................... 5-10
5.3.6 Input Circuitry .................................................. 5-10
5.3.7 Audio/Bias Mixing Circuitry ...................................... 5-11
5.3.8 Erase Head Driver ............................................... 5-11
5.3.9 Reel Control Board .............................................. 5-12
Section 6 Alignment
6.1 Transport Alignment ............................................... 6-2
6.1.1 Transport Deck Plate ............................................. 6-2
6.1.1.1 Opening and Closing the Transport Deck ................... 6-2
6.1.1.2 Removing the Transport Deck Plate ........................ 6-3
6.1.1.3 Reinstalling the Transport Deck Plate ...................... 6-4
6.1.2 Head Geometry .................................................. 6-4
6.1.2.1 Reproduce Head Azimuth .................................. 6-5
6.1.2.2 Record Head Azimuth ......................................6-5
6.1.3 Swing Arm Travel ................................................ 6-6
Table of Contents
viii
April 1992
MTR-90III Operation and Maintenance Manual