National SG-990A High Quality Service Manual

High quality reproduction of original factory service manual. The manual describes SG-990A AM/FM multiplex stereo radio-phono with stereo cassette tape recorder. The manual includes circuit diagrams, parts catalog, specification and more. Refer to table of contents for more information.

• Specifications

• Parts Identification

• Disassembly Instructions

  • To Remove Chassis

  • To Remove Cassette Tape Deck

  • To Remove Record Changer

  • To Remove Speaker

  • To Remove Baffle Board

• Schematic Diagram

• Alignment Instructions

  • AM – IF & FM Alignment

  • Alignment Points

  • FM – RF Alignment & FM Stereo Alignment

  • FM Stereo Alignment

• Parts Identification (Printed Circuit Board)

• Circuit Board Wiring View

• Alignment Instructions (Tape Recorder)

• Mechanical Adjustment – Tape Recorder

• Tape Transport Operations

• Parts Identification – Tape Deck

• Dial Cord Stringing Guide

• Tape Recorder Circuits

• Trouble Shooting Guide

  • Defective Recording Circuit

  • Defective Playback Circuit

  • Defective Mechanism

• Exploded View of Cassette Deck

• Servicing the Record Changer

• Record Changer Replacement Parts List

• Cassette Tape Recorder Replacement Parts List

• Replacement Parts List