Mattel Football II Capacitor Replacement Guide
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Capacitors on the main board of the Mattel Football II handheld LED game (model 1050, 1978), the board marked MATTEL 1050-4369D.[1] Mattel published no parts list, schematic or board layout for the game and no photograph of the component side of the board has been published, so the number, positions and values of its electrolytic capacitors are not on record. What is known about the circuit is set out below, with a method for recording and replacing the capacitors on your own board.
No Football II fault caused by a capacitor has been reported. Replace a capacitor when it is visibly leaking or bulging, or when a measurement points to it. See Capacitor Failure Symptoms.
What is known about the circuit
[edit | edit source]| Item | Detail | Source |
|---|---|---|
| Supply | One 9-volt battery on a snap; a Mattel AC adaptor through a socket on the left side, on games that have one. No adaptor rating is published | [2][3] |
| Main board | MATTEL 1050-4369D | [1] |
| Game chip | Rockwell MM77LA, marked B8000-12 | [1] |
| Clock | The chip's oscillator, set by a resistor; MAME's notes give 56 kΩ | [1] |
| Display | Seven 7-segment LED digits and 30 other LEDs | [1] |
| Sound | Two-level output from the chip to a speaker | [1] |
The game's speed depends on the oscillator resistor named in MAME's notes, so a game that runs at the wrong speed on a fresh battery points to that resistor and its joints before any capacitor.[1]
Recording your board
[edit | edit source]- Take the battery out and open the case; see Mattel Football II General Maintenance.
- Photograph both sides of the board before touching anything.
- List every electrolytic capacitor: its position relative to the game chip and the snap leads, its value, voltage and temperature rating, and which way its stripe faces.
- Look for residue on the board round each one, a swollen top, or a part leaning on its leads.
- Keep the list and photographs with the game: for this board they are the only record of its parts.
Replacement
[edit | edit source]- Fit radial electrolytics of the same capacitance and at least the same voltage rating, 105 °C, and no larger than the originals.
- Anything across the supply should be rated comfortably above 9 V. On games with an adaptor socket, where an unregulated adaptor can deliver more than its label, use 16 V or more.
- Observe polarity, and clean off flux with isopropyl alcohol before refitting the board.
After the work
[edit | edit source]- Run the switch-on check on Mattel Football II Troubleshooting Guide: PRO 1 gives 15.0 on the scoreboard and the kick-off formation, and KICK plays the "CHARGE!" tune and the start buzzer.[3]
- Check all four speeds: PRO 1 and PRO 2, then each again with KICK held at switch-on.[3]
Related pages
[edit | edit source]- Mattel Football II
- Mattel Football II General Maintenance
- Mattel Football II Troubleshooting Guide
- Mattel Football Capacitor Replacement Guide: the 1977 original
- Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 MAME source, hh_pps41.cpp (retrieved 2026-10-19): Mattel Football 2 (model 1050), PCB label MATTEL, 1050-4369D; MM77LA MCU labelled B8000-12; 7 seven-segment LEDs, 30 other LEDs, 2-bit sound; clock "approximation - VC osc. R=56K".
- ↑ Mattel, Inc., Here's How to Play Football II (1978, 1050-0920), File:Mattel Football II Instructions (1978).pdf: PDF p. 2, one 9-volt battery, or the Mattel Electronics AC adapter "if your game is equipped for an adapter"; printed p. 1, the AC adaptor plug on the left side.
- ↑ 3.0 3.1 3.2 Mattel, Inc., How to Play Football II (1978, 1050-0920(B)), File:Mattel Football II Instructions (1978, revision B).pdf: p. 2, 9-volt battery and Mattel AC adaptor, the four speeds; p. 4, the switch-on sequence (15.0, kick-off formation, "CHARGE!" tune and start buzzer). No adaptor rating is given.