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Magnavox Odyssey 400 Capacitor Replacement Guide

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Magnavox Odyssey 400 BG7516 board layout (SM 6505)
Component view of the BG7516 (Odyssey 400) board, with every capacitor position labelled (Magnavox Service Manual No. 6505, p. 6505-5)

The Magnavox Odyssey 400 (BG7516) has fifteen electrolytic capacitors on its single board. Magnavox's Service Manual No. 6505 lists each one's value, voltage rating and part number, and the BG7516 schematic prints the same values and ratings beside the parts, so the two documents agree. The component-side drawing of the board shows where they sit.[1][2][3] For failure signs in general see Capacitor Failure Symptoms.

Before replacing anything

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The console runs from six C cells or a 9 V adaptor, so there are no mains voltages inside it.[4] Magnavox's documents name no capacitor as a known fault. Check the supply first: +9 V at W1, 9.6 V at IC1 pin 2 and 4.5 V to 5.5 V at IC1 pin 3.[4][5][2]

Electrolytic capacitors

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Odyssey 400 (BG7516) electrolytic capacitors
Ref Value Rating Magnavox part no. Circuit (schematic) Beside (board drawing)
C2 470 µF 16 V 270109-5215 9 V supply from power switch S1, before L3 (68 µH) and IC1 pin 2 Battery terminal W2
C9 220 µF 16 V 270109-2215 Regulated 5 V line from IC1 pin 3 IC1, near the "5V REG" marking
C10 22 µF 25 V 270111-2125 IC1 pin 8, with R12 (100 kΩ) Rebound controls R8 and R10
C11 22 µF 25 V 270111-2125 IC1 pin 4, with R13 (100 kΩ) Rebound controls R8 and R10
C12 2.2 µF 50 V 270109-2050 IC4 pin 5, with R19 (150 kΩ) IC4
C19 2.2 µF 50 V 270109-2050 IC4 pin 12, with R20 (150 kΩ) Left fixed player control R33
C44 2.2 µF 50 V 270109-2050 IC2 pin 3, right player horizontal control R41 Right player horizontal control R41
C45 2.2 µF 50 V 270109-2050 IC2 pin 14, left player horizontal control R43 Left player horizontal control R43
C46 2.2 µF 50 V 270109-2050 IC2 pin 5, right player vertical control R45 Right player vertical control R45
C47 2.2 µF 50 V 270109-2050 IC2 pin 12, left player vertical control R47 Left player vertical control R47
C52 10 µF 25 V 270111-1125 IC3 pin 5, the ball control input IC3
C56 47 µF 16 V 270111-5115 IC3 pin 3, with the SPEED control R51 SPEED control R51
C62 4.7 µF 50 V 270111-5050 IC6 pin 3, fed through R68 (10 kΩ) IC6
C65 10 µF 25 V 270111-1125 IC5 pin 6, fed through R72 (47 kΩ) Left player horizontal control R43
C74 47 µF 16 V 270111-5115 IC7 pin 2, with R86 (33 kΩ) and diode D12 IC7
C76 47 µF 16 V 270111-5115 IC7 pins 12 and 13, with R87 (68 kΩ) IC7

[1][2][3]

The board drawing also shows outlines labelled C1, beside C2, and C73, near the left player vertical control R47, which appear in neither the BG7516 schematic nor its parts list. The same drawing shows positions for transistors Q10, Q11 and Q12, which are not in the parts list either. Leave those positions empty.[3][1][2]

Several values differ from the Odyssey 200's: C10 and C11 are rated 25 V here against 10 V there, C62 is fed through 10 kΩ against 33 kΩ, and C74 and C76 belong to IC7, which the 200 does not have.[1][2]

Other capacitors

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The remaining capacitors are polyester film, polystyrene and ceramic types. Capacitors not listed separately are 10 %, 500 V parts unless the schematic says otherwise.[1]

  • The timing capacitors are 2200 pF 5 % ceramic (C3, C14, C18, C41, C43, C48, C50) and 0.47 µF 5 % polyester (C13, C17, C40, C42, C49, C51).[1]
  • The RF section around Q1 and Q2 uses NPO ceramic capacitors and a 3–15 pF trimmer, C24, which sets the oscillator. Leave it alone during a recap.[1][2]

Procedure

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  1. Take out the cells and unplug the adaptor.
  2. Remove the bottom cabinet and the board, as described on the maintenance page.
  3. Photograph the board and note the polarity of each capacitor before removing anything.
  4. Fit capacitors of the same value and at least the same voltage rating as the parts list gives.[1]
  5. Clean off flux, refit the board, and check +9 V at W1 and 4.5 V to 5.5 V at IC1 pin 3.[4][2]
  6. Check the picture, then repeat the frequency, blanking, rebound, fixed player and score spacing adjustments if needed.[6]
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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Magnavox, Service Manual No. 6505, November 1976, p. 6505-10: BG7516 replacement parts list (coils, capacitors with type, value, rating and part number, controls and switches, semiconductors, miscellaneous) and cabinet replacement parts list. Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Magnavox, Service Manual No. 6505, November 1976, pp. 6505-7 to 6505-9: BG7516 schematic diagram, with capacitor values and electrolytic voltage ratings, IC6 (612108), IC7 (612084) and Q13, the RF section and the antenna switch board. Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.
  3. ↑ 3.0 3.1 3.2 Magnavox, Service Manual No. 6505, November 1976, p. 6505-5: main P.C. board (component view), board 210996-9. Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.
  4. ↑ 4.0 4.1 4.2 The Magnavox Company, Service Manual No. 6505: BG7516 Odyssey, first issue, November 1976, p. 6505-1: general information (6 C cells or an optional AC to DC 9 V adapter; Hockey, Tennis and Smash; two or four players in Tennis and Hockey; digital on-screen scoring) and the specifications table. Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.
  5. ↑ Magnavox, Service Manual No. 6505, November 1976, p. 6505-3: voltage charts for IC1 to IC7 and transistors Q1, Q2, Q4, Q5 and Q13 (VTVM; Tennis; players switch at 2; sound on; channel 3; players centred; ball volleying), notes 1 to 14, and the IC functions. Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.
  6. ↑ Magnavox, Service Manual No. 6505, November 1976, p. 6505-6: service adjustments (horizontal and vertical frequency, blanking width and centring with Figure 1, top and bottom rebound, right wall, goal opening, score indicator position, right and left fixed players). Hosted as File:Magnavox Odyssey 400 Service Manual 6505.pdf.


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