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Intellivision Keyboard Component General Maintenance

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Intellivision Keyboard Component cassette mechanism (Mattel Owner's Book)
The Keyboard Component's cassette mechanism, from Mattel's Owner's Book: the heads, the capstan and the pinch roller, which turns clockwise.

The Intellivision Keyboard Component (Mattel model 1149) carries the Master Component in a recess at the back, has its own mains transformer and power supply, and contains a computer-controlled cassette drive, which is the part that needs regular attention.[1][2] Mattel's own maintenance instructions are in the Owner's Book and the 1980 Service Manual, both hosted at Intellivision Keyboard Component Documentation. Care of the Master Component itself is on Intellivision General Maintenance.

Safety

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The Keyboard Component's power cord is the mains supply for the whole system: the Master Component's own cord plugs into an outlet inside the recess.[1] Unplug the Keyboard Component's power cord from the wall before taking the Master Component out or opening the case; Mattel's disassembly procedure starts with this step.[3]

Mains voltage is present in the transformer assembly and at its female receptacle, where Mattel's service manual expects 105–125 V AC. The power supply board itself runs from the transformer's secondary at 17–23 V AC.[4] Mattel's 1979 drawing of an earlier power supply shows reservoir capacitors of up to 15,000 µF, each with an 8.2 kΩ bleeder resistor across it.[5] Check that the large capacitors on your board have discharged before working on it, as on any supply of this kind; see Capacitor Failure Symptoms for signs of failed electrolytics.

Where to keep it

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Mattel asks for a flat, sturdy surface, away from direct sunlight, heat sources and air conditioners, with space between the air vents on the back and the wall.[6] When it is not in use, cover it with a clean cloth to keep dust out of the cassette drive. Static can build up in dry weather or in carpeted rooms; Mattel suggests anti-static spray on carpets and touching a metal surface before handling a cassette.[7]

Cleaning the cassette mechanism

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Mattel tells owners to clean the tape heads, capstan and roller "after roughly every 5 hours of use", with good quality cotton swabs and a commercial tape head cleaner.[7] The monitor program has a CLEAN command that drives the mechanism for cleaning without erasing or recording.[8]

  1. Go to the monitor. Type E and press RETURN to open the cassette housing.
  2. Type CL and press RETURN. The heads move forward and the roller starts turning.
  3. Wet a swab in the cleaner and remove the excess without touching it with your fingers; oil from your skin should not reach the heads.
  4. Clean the heads by rubbing the swab gently back and forth across them, not up and down.
  5. Hold the swab against the right-hand side of the roller (as seen from the front) as it turns, to clean the roller and capstan. Do not hold it against the left-hand side, where it can be pulled in between the capstan and roller.[7][9]

Do not use water, soap or a dry cloth on the heads, which leave a residue or scratch them, and do not use cleaning cassettes, which Mattel found too abrasive.[7] The service manual's drive maintenance step uses alcohol on a cotton swab, with the same warning about the left-hand side, and then checks that the heads move forward into the playback position and that the reel drive shaft turns.[9]

Tapes

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Store cassettes away from heat, cold, moisture and strong magnetic fields such as loudspeakers, the back of a television or a telephone, and take them out of the drive after use.[7] Mattel's cassettes carry a special coding and cannot be copied without a noticeable loss of quality.[8]

If a tape breaks or tangles in the mechanism, Mattel's emergency procedure is to stop the tape by typing CTRL-C twice, then run a credit card from back to front down the right side of the cassette housing, which trips the emergency eject and opens the door. Untangle the tape carefully. A wrinkled tape should not be used again; a tape that is not wrinkled can be wound back into the cassette with a pencil. The emergency eject does not rewind the tape, so it is not for normal use.[10]

Separating the Master Component

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Intellivision Keyboard Component Figure D board removal (Mattel)
Figure D of the service manual: the power supply board, held by three screws, and the logic board, held by 5/8-inch screws (corrected by hand to nine), in the lower housing.

Mattel's procedure:[3]

  1. Unplug the Keyboard Component's power cord from the wall.
  2. Unplug the RF adaptor (cable extender) from the Master Component through the opening in the Keyboard Component.
  3. Make sure both hand controllers are in their places on the Master Component.
  4. Turn the whole assembly upside down. Hold the Master Component in place with one hand and remove the five 8-18 × 1/2-inch screws that join the two units.
  5. Turn the assembly the right way up and ease the Master Component out of the recess, drawing the ribbon cable and power cord out of their storage pockets.
  6. Unplug the Master Component's power cord from the Keyboard Component's outlet, and pull the Keyboard Component's signal plug out of the Master Component's cartridge port.

Opening the case

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With the Master Component removed, turn the Keyboard Component upside down and take out the nine 8-18 × 5/8-inch screws that hold the upper and lower housings together. Stand the unit on its side and separate the housings carefully, then lay the upper housing upside down beside the lower one with their fronts touching. The keyboard and the tape deck are fixed to the upper housing; the logic board, power supply, transformer and tape control assembly are fixed to the lower housing.[3][2]

Cables

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Internal cables named in Mattel's removal procedures
Between Cable
Logic board and tape control assembly 20-conductor flat ribbon
Power supply and tape control assembly 6-conductor flat ribbon
Power supply and logic board Logic board power cable
Tape deck and tape control assembly Two 9-conductor flat ribbons
Tape deck preamp and tape control assembly 9-wire and 2-wire cables
Transformer and power supply Transformer assembly connector
Keyboard and logic board Keyboard cable

The cables are as described in the service manual's removal procedures.[3] Mattel's 1982 drawing list gives the tape ribbon as a 20-conductor cable (1149-7699), the power ribbon to the tape control as 6-conductor (1149-7679) and the logic board's power ribbon as 8-conductor (1149-7689).[11]

Removing the modules

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Mattel's procedures replace each module as a unit. Refit in the reverse order.[3]

Logic board

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Unplug the logic board's power cable from the switching power supply and its tape control cable from the tape control assembly. Remove the nine 8-18 × 5/8-inch screws, unplug the keyboard cable and lift the board out. The manual calls it the "Computer II" assembly.

Tape deck

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Unplug the two 9-conductor ribbons at the tape control assembly, and the 9-conductor and 2-conductor cables at the preamp on the tape deck. Remove the six 10-16 × 1/2-inch screws. Press the cassette eject solenoid by hand until the tape cover opens, then lift the deck out of the upper housing.

Switching power supply

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Unplug the logic board's power cable, the tape control power cable and the transformer connector, and fold the logic board's tape control cable back over the logic board. Remove the three 8-18 × 5/16-inch screws and lift the supply out.

Transformer

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Unplug the transformer connector from the power supply. Remove the two 8-18 × 5/8-inch screws holding the transformer's female receptacle and the four 10-16 × 3/8-inch screws holding the transformer.

Keyboard

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Unplug the keyboard cable from the logic board and remove the six 8-18 × 5/8-inch screws that hold the keyboard to the upper housing. Keep the six conical washers that sit under them.

Tape control assembly

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Unplug the two 9-conductor ribbons and the 9-wire and 2-wire cables from the tape deck, the 20-conductor ribbon from the logic board and the 6-conductor ribbon at the power supply. Remove the three 8-18 × 5/8-inch screws. Tilt the inboard edge up to clear the transformer and slide the assembly inwards so that the volume control knobs come out of the side of the lower housing.

An insulator (1149-0230) sits under the tape control assembly; put it back when refitting the assembly.[12][2]

Fuse

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The switching power supply carries fuse F1, a 3AG 5 A 250 V normal-blow fuse (Mattel part 0089-0803). Mattel's power test checks it first when the screen stays blank.[2][4] Replace it only with the same rating; a fuse that blows again points to a fault, covered on the Intellivision Keyboard Component Troubleshooting Guide.

Tape deck belts

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Mattel's drawing list names two belts in the tape deck, a clutch belt (1149-4079) and a flywheel belt (1149-4089), marked as normally supplied as part of the tape deck assembly.[11] No belt sizes or replacement procedure are given in the service manual, which replaces the whole tape deck. In Mattel's 1981 life test the commonest failures were tape stalls and torque adjustment faults.[13]

Capacitors

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What is known about the Keyboard Component's capacitors, including the values on Mattel's 1979 power supply drawing, is on the Intellivision Keyboard Component Capacitor Replacement Guide.

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References

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  1. ↑ 1.0 1.1 Mattel Electronics, Keyboard Component Owner's Book, pp. 3–5: the Master Component's power cord plugs into the outlet in the recessed area; the Keyboard Component's power cord goes to a 120 V AC ± 10%, 60 Hz wall outlet. File:Mattel Intellivision Keyboard Component Owner's Book.pdf.
  2. ↑ 2.0 2.1 2.2 2.3 Mattel Electronics, Keyboard Component Service Manual (1980), pp. 2–2A: parts list, including fuse 3AG normal 5 A 250 V (0089-0803) and the tape control insulator (1149-0230). File:Mattel Intellivision Keyboard Component Service Manual (1980).pdf.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Mattel Electronics, Keyboard Component Service Manual (1980), Section IV, pp. 14–17, and Figure D (PDF p. 25). File:Mattel Intellivision Keyboard Component Service Manual (1980).pdf.
  4. ↑ 4.0 4.1 Mattel Electronics, Keyboard Component Service Manual (1980), pp. 6–8A: fuse F1 on the switching power supply; 17–23 V AC at power supply board receptacle J1; 105–125 V AC at the transformer female receptacle. File:Mattel Intellivision Keyboard Component Service Manual (1980).pdf.
  5. ↑ Mattel Electronics, drawing 1149-9099, power supply schematic, 1979: C1 3300 µF, C2 6800 µF and C3 15,000 µF with R1, R2 and R3 (8.2 kΩ) across them. File:Mattel Intellivision Keyboard Component Power Supply Schematic 1149-9099 (1979).pdf.
  6. ↑ Mattel Electronics, Keyboard Component Owner's Book, p. 5, "Before final hook-up". File:Mattel Intellivision Keyboard Component Owner's Book.pdf.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 Mattel Electronics, Keyboard Component Owner's Book, p. 25, "Keeping your computer happy (Preventative Maintenance You Can Do Yourself)". File:Mattel Intellivision Keyboard Component Owner's Book.pdf.
  8. ↑ 8.0 8.1 Mattel Electronics, Keyboard Component Owner's Book, p. 24: the CLEAN command ("head cleaning mode. It will not erase or record") and the special coding of Mattel cassettes. File:Mattel Intellivision Keyboard Component Owner's Book.pdf.
  9. ↑ 9.0 9.1 Mattel Electronics, Keyboard Component Service Manual (1980), p. 12, tape test step 3, "Drive maintenance". File:Mattel Intellivision Keyboard Component Service Manual (1980).pdf.
  10. ↑ Mattel Electronics, Keyboard Component Owner's Book, p. 27, problem 5 and the emergency eject procedure. File:Mattel Intellivision Keyboard Component Owner's Book.pdf.
  11. ↑ 11.0 11.1 John H. Lishman, "Keyboard Component Drawing List" 1149-5829A, 1 June 1982. In Keyboard Component Plans (1982), PDF pp. 15–17. File:Mattel Intellivision Keyboard Component Plans (1982).pdf.
  12. ↑ Mattel Electronics, engineering decision memo 1149-269, 25 June 1981, Keyboard Component system level parts list, page 6 of 7: "Insulator, TCA (Inserted under Tape Control Assy)", 1149-0230. Internet Archive item 19810625KeyboardComponent.
  13. ↑ D. Bowen, "Intellivision Keyboard Quality", 23 November 1981, page 4, "Life test results to date". In Keyboard Component Plans (1982), PDF p. 4. File:Mattel Intellivision Keyboard Component Plans (1982).pdf.


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