Troubleshooting & Diagrams

XI. Trouble Shooting Chart

Section "A" Troubles with Amplifier

Section A troubleshooting flow-chart for amplifier troubles: playback problems branching through B+ voltage checks, hum, noise, treble loss, and distortion symptoms to their causes and remedies

1. Playback problems. (Unit set in play position.)

• No sound from Line-out jack
  • B+. voltage not supply
    • Silicon diode SW05-01 or R4-91Ω 1W defective
      • Replace
  • B +. voltage supply
    • Playback amp. card and socket loose connect
      • Adjust
    • P-108, J-8 loose connect
      • Adjust
    • Check transistors TR-1, TR-2, TR-3, and TR-4
    • Playback head coil opens or lead wire takes off
• Sound comes out but volume insufficient
  • B+. voltage low
    • Silicon diode SW05-01, R4 91Ω, C1 500μF defective
      • Replace
  • B +. voltage normal
    • Dust adhering to head
      • Clean
    • Check transistors TR-1,2,3 and TR-4
• Loud hum
  • Hum is decreased if playback head is grounded
    • Hum bucking coil out of adjustment
      • Readjust
    • Playback head shield or insulation defective
      • Replace.
  • No change even when grounding playback head
    • Ground wire take off
      • Adjust
    • C1 500μF, C2 1,000μF defective
      • Replace
  • Inductive pick up
    • Ground the recorder
    • Change the set position of the recorder
• Irregular scratching or crackling noise
  • Playback card and socket loose connection
    • Adjust
  • Transistor TR-1, TR-2 defective
    • Replace
• Squeak noise
  • Dust adhering to head surface
    • Clean
  • Tape itself
    • Replace
• Hissing noise
  • Noise comes out when playing tape
    • Head is magnetized
      • Demagnetize head
    • Tape itself noisy
      • Replace
  • Not caused by tape
    • Transistors TR-1,2 defective
      • Replace
• Lack of treble
  • Poor contact between head and tape
    • Dust adhering to head surface
      • Clean
    • Back tension weak
      • Adjust tension of supply spindle
  • Head angle incorrect
    • Re-adjust head angle
  • Head worn out
    • Replace
  • Tape itself defective
    • Replace
• Sound distorted
  • Dust adhering to head surface
    • Clean the head
  • Defective transistors
    • Replace
  • Head worn out
    • Replace

Section "B" Troubles with Tape Transport Mechanism

Section B troubleshooting flow-chart, sheet 1 of 2: tape transport troubles from capstan rotation faults through take-up, wow-and-flutter, and fast-forward symptoms to their causes and remedies

• Capstan does not rotate.
  • Troubles with motor.
    • Broken field coil.
      • Check field coil with tester, and replace motor if coil is broken
    • Defective motor starting capacitor C6.
      • Replace C6.
    • Rotor shaft dragging due to lack of oil.
      • Overhaul motor. Clean and re-lubricate oilite metal
    • Some foreign matter exists between rotor and stator.
      • Check and eliminate foreign matter for free rotation of rotor.
  • Troubles with power transmission mechanism.
    • Broken capstan drive belt.
      • Replace belt
    • Capstan drive belt off of driving position.
      • Place belt in position
    • Motor bushing slipping on motor shaft.
      • Tighten mounting screw.
    • Oil attached to motor bushing and/or flywheel
      • Wipe off oil with cotton swab soaked in alcohol.
• Capstan rotates in Stop position, but tape does not advance when switched to Play position.
  • Troubles with motor
    • Decreased motor torque.
      • Check motor torque and replace motor.
    • Defective C6.
      • Replace C6.
    • Motor bushing slipping on motor shaft
      • Tighten mounting screw
  • Troubles with power transmission mechanism.
    • Capstan drive belt stretched up.
      • Replace belt
    • Oil attached to motor bushing and/or flywheel
      • Wipe off oil
    • Capstan bushing silping[sic] on flywheel shaft.
      • Tighten capstan mounting screw.
    • Excessive tension in Take-up Supply reel table assembly
      • Readjust tension
    • Oil attached to capstan and/or pinch wheel
      • Wipe off oil.
    • Insufficient pinch wheel pressure
      • Check and re-adjust pinch wheel pressure.
• Capstan advances tape, but take-up reel does not take up tape.
  • Reel shaft dragging due to lack of oil
    • Check take-up reel shaft assembly
  • Take-up idler wheel does not rotate properly.
    • Check idler wheel. Replace if necessary
  • Oil attached to idler wheel and roller on take-up reel shaft assembly.
    • Wipe off oil.
  • Take-up idler wheel does not keep good contact.
    • Check idler tension spring. Replace spring if necessary
    • Check lever "[illegible]."
• Take-up functions normally, but tape speed lower than regular speed.
  • Troubles with motor
    • Rotor shaft dragging due to lack of oil
      • Overhaul motor. Clean and re-lubricate oilite metal
    • Defective motor starting capacitor (C30).
      • Replace C30.
  • Fluctuation in power supply.
    • Check line voltage and cycle. Use voltage regulator if line voltage is lower than standard.
  • Troubles with power transmission mechanism.
    • Capstan drive belt stretched up and slipping on motor bushing
      • Replace belt.
    • Capstan drive belt not in correct driving position.
      • Place belt in position.
    • Oil attached to motor bushing and/or flywheel.
      • Wipe off oil.
• Wow-flutter. Irregular tape movement.
  • Troubles with motor.
    • Decreased motor torque.
      • Check motor torque.
    • Defective motor starting capacitor (C6).
      • Replace C6
  • Troubles with power transmission mechanism.
    • Take-up/supply reel shaft dragging or excessive tension
      • Check reel shaft assemblies. Replace reel shaft assembly if tension not adjustable.
    • Capstan drive belt stretched up and slipping
      • Check belt.
    • Unbalanced flywheel rotation
      • Check balance. Replace flywheel.
    • Rubber on pinch wheel deteriorated
      • Check rubber on pinch wheel and replace pinch wheel.
    • Pinch wheel or tape guide does not rotate smoothly
      • Check and replace defective part. Clean and re-oil if it again provides smooth rotation.
    • Dust on heads.
      • Clean heads.
    • Insufficient pinch wheel pressure.
      • Re-adjust pinch wheel pressure.
    • Capstan bushing slipping on flywheel shaft.
      • Tighten capstan mounting screw.
    • Worn-out idler wheel or no oil.
      • Replace worn-out idler. Lubricate oilite metal in center of idler.
• Unit does not operate in Fast Forward mode.
  • Take-up reel shaft does not rotate even without placing recording tape on unit.
    • Troubles with power transmission mechanism.
      • Oil attached to take-up idler wheel or motor bushing.
        • Wipe off oil.
      • Loose motor bushing.
        • Tighten motor bushing mounting screw
      • Take-up idler wheel does not function properly.
        • Check and readjust idler wheel.
      • Take-up reel shaft assembly does not function properly.
        • Check, clean and re-oil reel shaft assembly.
      • Check lever "[illegible]".
  • Take-up reel shaft does not rotate when recording tape is placed on unit.
    • Troubles with motor.
      • Decreased motor torque.
        • Check motor torque. Replace motor if required.
      • Defective motor starting capacitor (C6).
        • Check and replace C6
    • Troubles with power transmission mechanism.
      • Excessive slippage of clutch material (felt) in take-up reel shaft assembly.
        • Check take-up reel shaft assembly
      • Tape guide roller does not rotate smoothly.
        • Check guide roller. Re-oil or replace
    • Defective reel
      • Take-reel warped and sticking to deck top panel.
        • Check and replace reel.

Section B troubleshooting flow-chart, sheet 2 of 2: rewind, brake, automatic-stop, and cycle-change-switch troubles, continuing Section B onto a second page with the same header

• Unit does not rewind tape.
  • Supply(rewind) reel shaft does not rotate even without placing recording tape on unit.
    • Troubles with power transmission mechanism.
      • Oil attached to rewind idler or motor bushing
        • Wipe off oil.
      • Intermediate idler (black bakelite wheel) not working correctly.
        • Check internal idler.
      • Loose rotor bushing.
        • Tighten motor bushing mounting screw
      • Rewind idler does not rotate or not in position.
        • Check rewind idler. Clean and re-oil.
      • Supply reel shaft assembly does not rotate smoothly.
        • Check supply reel shaft assembly. Clean and re-oil.
  • Supply(rewind) reel shaft does not rotate when tape is placed on unit.
    • Troubles with motor
      • Decreased motor torque
        • Check motor torque. Replace motor if not repairable.
      • Defective motor starting capacitor C6.
        • Replace C6.
    • Trouble with power transmission mechanist[sic]
      • Excessive slippage of clutch material (felt) in supply reel shaft assembly.
        • Check supply reel shaft assembly.
      • Tape guide roller does not rotate.
        • Check guide roller. Re-oil or replace.
    • Defective reel
      • Supply(rewind) reel warped and sticking to deck top panel
        • Check and replace reel.
• Loose tape winding after being placed in Rewind or Fastforward mode
  • Decreased back tension of take-up and supply reel shaft assemblies.
    • Disassemble reel shaft assemblies and strengthen back tension
• Tape spills when stopped from Rewind or Fast forward mode.
  • Excessive slippage of felt clutch material in take-up and rewind reel shaft assemblies.
    • Readjust slippage of felt clutch material. Replace defective reel shaft assembly if this readjustment is difficult
  • Reels of different size are used. For example, 5" reel on take-up side and 7" reel on supply side.
    • Always use reels of same size on both sides.
• Break[sic] does not function properly.
  • Worn-out brake shoes
    • Check and replace brake shoes.
  • Oil attached to surface of brake shoes.
    • Wipe off oil with cotton swab soaked in alcohol.
  • Loose brake shoes
    • Tighten brake shoes mounting screw.
  • Brake lever does not function properly
    • Check and re-adjust brake lever.
• Periodical clack noise when rewinding or fast forwarding tape
  • Worn-out and rugged idler wheel.
    • Check idler wheel.
• Loud motor vibration.
  • Loose motor mounting screw
    • Tighten mounting screw
  • Defective motor starting capacitor (C6)
    • Replace C6.
  • Loose oil cover mounting screw.
    • Tighten mounting screw
• Squeaking noise when playing tape.
  • Deposit of dust on heads.
    • Clean heads.
  • Recording tape is being charged with static electricity.
    • Replace recording tape.
  • Excessive heat on head surface after continued operation.
    • Check tape head.
  • Old and worn-out recording tape.
    • Inspect recording tape.
  • Inferior recording tape
    • Use recording tape of good quality.
• Automatic stopping device does not function.
  • Automatic stop lever moves normally.
    • Micro switch (SW-5) does not work properly
      • Check SW-5.
  • Automatic stop lever does not move or sticky.
    • Broken lever spring or lever spring not in position.
      • Check lever spring.
    • Automatic stop lever sticks to rear deck panel
      • Check rear side of deck sub-plate.
• Cycle change switch does not move.
  • No lubricant on cycle conversion lever.
    • Relubricate lever.
  • Eccentric or bent cycle conversion lever.
    • Check cycle conversion lever.
  • Capstan drive belt not on driving track of flywheel.
    • Check capstan drive belt
  • Loose motor bushing.
    • Tighten mounting screw.
  • Loose motor mount screw.
    • Tighten mounting screw.
  • Oil on motor bushing or on flywheel.
    • Wipe off oil with cotton swab soaked in alchol.[sic]

XIII. Connecting Diagram

Connecting diagram: the X-150D reel-to-reel deck at center, wired to left and right speakers, a stereo pre-main amplifier, an AC power source, two stereo headphones, a stereo microphone pair, a stereo player (turntable), and a stereo tuner, with a handwritten signature at the bottom right of the sheet

• SPEAKER(LEFT)
• SPEAKER(RIGHT)
• STEREO PRE·MAIN AMP
• AC. POWER SOURCE
• STEREO HEADPHONE
• STEREO HEADPHONE
• (L) MIC. (R)
• STEREO PLAYER
• STEREO TUNER
• RECORDING