Section One: Preliminary
Section Two: Unit Disassembly and Reassembly
Section Three: Troubleshooting Guide
Section Four: Selected Repair/Adjustment Procedures
Section Five: Suggested Spare Parts

Tools Required                Equipment Required:

5/16" Nut Driver                Volt/Ohm Meter
1/4" Nut Driver                 Function Generator
Flat Blade Screwdriver          Calibrated Oscilloscope
Phillips Screwdriver
Soldering Iron and Solder
Needle Nose Pliers

Maintenance to the LMS102A units is easier to perform with the unit removed from the case. All electronics are attached to the panel; there are no connections to the case bottom.

To detach the panel from the case, follow these steps:

1. With the unit on a flat surface and the top cover removed, loosen the six quarter-turn fasteners on the front panel along the side and front edges.
2. Stand the unit on one side and swing open the front edge (note that the panel is hinged to the case bottom at the rear edge).
3. Inside the case along the rear edge, locate the four 5/16" nuts holding the hinge to the case bottom. Remove the four nuts.
4. Carefully return the unit to the flat position. Using the handles, lift the panel up and away from the case bottom. It may be necessary to "jockey" the panel around to free it from the screw studs in the case bottom.
5. Place the panel on a sturdy flat work surface, preferably one which is protected from static discharge.

Reinstalling into the suitcase:

1. Lay the unit FACE DOWN on the work surface.
2. Position the case bottom so that the four holes in the hinge slide over the screw studs in the case bottom. Install the nuts.
3. Before tightening the nuts, stand the unit on its side and push the panel as far to the rear of the case as possible. Tighten the nuts.

Problem: The unit does not power up.

Possible Solutions:

1. Ensure that the power connections are correct. Power is supplied through the POWER connector next to the ON/OFF switch. Power is not provided through the PEN REGISTER input. If pen register equipment is used to activate recording, the LMS102A must still have separate power through the POWER input.
2. The fuse on the power supply may have blown. Replace the fuse with a 5 amp 250 volt fast blow fuse.
3. Capacitor C6 on the power supply board may have broken loose. C6 is the large black can capacitor on the right front of the power supply.

   If this is the case, see Replacing C6 on the Power Supply Board in this guide.

Problem: Power seems to be on, but one or more decks do not operate.

Possible Solutions:

1. Cassette may not be installed properly. Eject and reinsert the cassette, ensuring that it is completely seated in the cassette well.
2. Deck assembly fuse may be blown. See Checking and Replacing Deck Fuses in this guide.

   NOTE: Some of the earliest versions of the LMS102A do not have fuses on the deck assembly.

Possible Solutions:

1. The record/playback heads may be dirty. Clean using a cotton swap soaked with ordinary isopropyl alcohol. At the same time, it would be best to clean the pinch roller and capstan assemblies. DO NOT apply any kind of lubricant to these areas.
2. The headbar may not be fully engaging. This is a mechanical problem that requires special adjustment tools to correct. To test for this problem, follow these steps:
   1. Insert a blank tape and engage record. (A convenient method to engage record is to insert a 1/4" phillips screwdriver shaft into the DISCOVERY jack. This will close the contacts. DO NOT FORCE the screwdriver into the jack.)
   2. With a known good audio source connected to the input of the unit, monitor the audio.
   3. Gently apply pressure to the headbar so that it is moved farther into the cassette. If the sound improves significantly, then the deck must be recalibrated.
   4. If the sound quality worsens, then release the pressure and gently apply pressure in the opposite direction (away from the cassette). Again, if the sound improves significantly, then the deck must be recalibrated.

      Recalibration should only be done at the factory. Return the entire unit to Phi Tech for repair.

3. The bias and/or record levels may be out of calibration. This occurs as a natural result of component aging. See Checking and Adjusting the Bias and Record Levels in this guide.

Problem: One or more indicators do not light.

Possible Solution:

Lamps in indicators are burned out. See Replacing Lamps in this guide.

Problem: VU's flash without any input signal

Possible Solution:

Check the play head wiring. It may need to be resoldered to the head. If so, it is best to send the unit to Phi Tech for repair.

Problem: The unit is in record mode, but nothing is going on the tape.

Possible Solutions:

1. Ensure that the input level switch on the main circuit board inside the unit is set to -20 dB.
2. Check the record head wiring. It may need to be resoldered to the head. If so, it is best to send the unit to Phi Tech for repair.

Problem: Rewind and cue-up time is taking longer than normal.

Possible Solution:

Normal end-to-beginning rewind time for a C-90 tape is less than 65 seconds. If the rewind time is significantly longer, the reel belts may be worn. It is recommended that the belts be replaced after 2,000 hours of operation.

Problem: Excessive wow/flutter.

Possible Solution:

Although wow and flutter is present to a small degree in all tape recorders, it is usually imperceptible, especially in voice or other non-music applications. If the wow and flutter levels become noticeable, the most common cause is a worn capstan belt. It is recommended that the capstan belts be replaced every 2,000 hours of operation. Although replacing the belt itself is not a difficult task (see Replacing Capstan Belt in this guide), it is recommended that the work be performed by the factory to ensure that wow and flutter levels are kept to an absolute minimum.

There are other factors which affect wow and flutter, but anything other than the belt must be factory-repaired.

Problem: When the recorded tape is played on another machine, the audio appears to be faster or slower than normal.

Possible Solutions:

1. The motor speed is misadjusted. Normally motor speed remains constant for the life of the deck, but the are occasions when age changes the electrical characteristics of the motor.

   Exact motor speed adjustment requires proper tools and is best done at the factory. However, for quick and emergency adjustment, see Setting the Motor Speed in this guide.

2. The capstan belt may have shifted in its path on the motor pulley and the flywheel. Check to see that the belt rides in the center of the motor pulley, and on the larger diameter surface of the flywheel. See Changing the Capstan Belt for instructions on accessing the belt.

Replacing C6 on the Power Supply Board

If C6 has broken loose from the power supply board, follow these steps to correct the problem:

1. Remove the four nuts holding the motion control/record board for deck #3.
2. Lift the board away from the deck to allow access to the two nuts holding the rear of the power supply bracket.

   Note: Steps a and b may not be necessary if the shaft of the 5/16" nutdriver you are using is long enough to reach the nuts holding the rear edge of the power supply bracket.

3. Loosen the two nuts at the rear edge of the power supply bracket. The holes in the bracket are slotted so it is not necessary to remove the nots entirely.
4. Remove the two nuts at the front of the power supply bracket.
5. Lift the front of the bracket away from the panel, and slide the rear of the bracket forward to free the rear edge from the screw studs.
6. Disconnect all connections to the board. Lay the power supply/bracket assembly on a work surface with the bracket feet in the air.
7. Remove the four screws securing the power supply to the bracket and remove the power supply from the bracket.
8. Reinstall the capacitor to the board. **Observe the proper polarity. Critical Note: If the capacitor is installed improperly, severe damage to the entire unit could result, as well as the possibility of injury to personnel.
9. To reinstall the power supply, reverse the above steps. When connecting the cables, ensure that the connectors are returned to the proper sockets on the board, and that all pins are aligned in the sockets.

Checking and Adjusting the Bias and Record Levels

Checking the levels:

1. Input a 2.2 volt p-p 250 Hz sine wave into the audio input jack on the front panel.
2. On the front panel circuit board inside the unit, locate the -20 dB/0 dB switch (SW3) and set it to 0 dB.
3. Insert blank tapes into each of the decks.
4. Place the unit into record by closing the contacts of the DISCOVERY jack.
5. If operating properly, each of the three VU meters should display 0 VU (fourth bar from the top, seven bars in all). Some minor fluctuation is normal, depending upon the quality of the tape.

Adjusting the levels:

If the levels are out of range or fluctuate greatly, or if the sound is distorted, the levels will need to be recalibrated. Ordinarily it is best for this procedure to be done by a factory technician using the proper tools and equipment. However, for emergency situations, the following steps can be performed:

1. Set the front panel MONITOR SELECT switch to monitor deck 1. Adjust the speaker volume to a comfortable level.
2. On the deck one's motion control/record board, locate adjustment controls P1 and P3. NOTE: It is not necessary to remove the boards from the deck assembly to make these adjustments. Holes are provided through the board for access to the controls with a small adjustment tool.
3. With an adjustment tool (a small flat-blade screwdriver is typical), rotate the control to the far counter-clockwise point. At this point, the audio will fade to very low, or cut out entirely.
4. Monitoring the audio and watching deck one's VU meter, slowly rotate the control clockwise. Soon the audio will begin to fade in, and will likely be distorted. Continue the rotation until the audio level peaks and begins to fade again. When this occurs, reverse the rotation until the audio level is at its peak. It may require several adjustments to find the peaking level. Ensure that the audio is also clear, without distortion.
5. Adjust P1 so that the VU meter indicates 0 VU (fourth bar from the top, seven bars in all).
6. Repeat this procedure with decks two and three, selecting the appropriate deck with the MONITOR switch.

Replacing Lamps

NOTE: Earlier production units had different types of sockets. One uses a "bi-pin" lamp, Phi Tech part number 1600-013, and has a bezel in addition to the lens. The older brand uses a round lamp Phi Tech part number 1600-008, and only has a lens.

For the RECORD/MINIMIZE buttons:

1. Using a small screwdriver, pry the lens cap off the switch.
2. Grasp the bulb with needle nose pliers and carefully pull the bulb straight out (sometimes it is easier and safer to place short pieces of small diameter rubber tubing over the tips of the pliers. This will provide more traction for gripping the bulb).
3. Install the replacement lamp and replace the lens.

For the OFF HOOK indicator:

1. Using a small screwdriver, remove the lens and the white insert.
2. Push the bulb from the top and remove the bulb and retainer.
3. Install the replacement bulb (1600-012) into the retainer.
4. Reinstall the retainer and bulb into the insert.
5. Reinstall the insert into the socket and replace the lens.

Replacing the Capstan Belt

Note: Although the capstan belt is field-replaceable, it is recommended that the procedure be performed by factory technicians to ensure a minimal amount of wow and flutter.

1. Locate and remove the four 5/16" nuts securing the Motion Control/Record board on the deck assembly.
2. Although not necessary, for convenience it is best to disconnect all connectors from the board and lay it aside.
3. Locate the capstan belt which extends between the large brass flywheel and the capstan motor pulley.
4. Remove the old belt and discard.
5. Install new belt in the place of the old belt. Caution: The ends of the capstan flywheel are lubricated with grease. Avoid getting the grease on the belt. Although the grease can be cleaned off with alcohol, the belt will still be permanently affected.
6. Reinstall and reconnect the motion control/record board.

Using this method would likely require repeating these steps until the desired speed is found.

The following parts are suggested for a minimal stock of spare parts.

Phi Tech #      Description                     Cost
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1600-008        Round Lamp for                  $ 8.64
                Record/Minimize Indicator         
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1600-012        Lamp for Off Hook Indicator     $ 8.00
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1600-013        Bi-Pin Lamp for Record/Minimize $11.12
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4100-020        Capstan Belt                    $33.84
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4100-025        Reel Belt                       $ 2.32
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8500-028        0.75 amp slow blow fuse         $ 6.40
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Title III       Places unit in record mode      $18.00
Tester          thru DISCOVERY connector              
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