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Atari Falcon Capacitor Replacement Guide

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Atari Falcon030

The Atari Falcon030 main board uses axial aluminium electrolytics, a few tantalum capacitors on the video encoder boards, and surface-mount ceramics for decoupling. Atari's parts list in the Falcon030 Service Guide gives every capacitor on the main board with its value, rating and part number.[1] The power supply and the memory boards are listed only as assemblies, so Atari gives no capacitor list for them.[1]

Board variants

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Atari made four main boards: CA401332-001 (NTSC), -002 (PAL-I), -003 (PAL-B) and -004 (Peritel). They share most parts; the NTSC, PAL-I and PAL-B boards add the video encoder and RF modulator section, which carries some of the electrolytics below. The Peritel board does not have those parts.[1]

Capacitor list

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All main boards

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Falcon030 main board electrolytics common to all variants (Atari parts list)
Designators Value Rating Type Atari part number
C147 4700 µF 16 V Electrolytic, axial C101205-472
C96 470 µF 35 V Electrolytic, axial C070450-008
C57, C121 220 µF 16 V Electrolytic, axial C303021-227
C29, C110 100 µF 16 V Electrolytic, axial C070499-004
C54, C56, C83, C84, C138 47 µF 16 V Electrolytic, axial C303021-476
C1 22 µF 16 V Electrolytic, axial C070499-001
C88, C91, C141 10 µF 50 V Electrolytic, axial C101212-100
C2, C6, C11, C67 4.7 µF 25 V Electrolytic, axial, 18 mm C070450-101
C92, C127 3.3 µF 50 V Electrolytic, axial C101212-3R3
C78 2.2 µF 50 V Electrolytic, axial C101212-2R2
C48, C181 1 µF 50 V Electrolytic, axial C101212-010
C7 0.1 µF 50 V Electrolytic, axial C302985-001

That is 25 electrolytics on every board. C48 also appears in the NTSC, PAL-I and PAL-B lists at the same value.[1]

C147 is the board's only 4700 µF part. exxos lists replacing it as a mandatory fix: a new low-ESR bulk capacitor there has cured some DMA sound faults, and it absorbs voltage spikes from an ageing supply, which he says tend to kill the VIDEL first.[2]

NTSC, PAL-I and PAL-B boards only

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Falcon030 electrolytic and tantalum capacitors on the encoder boards (Atari parts list)
Designators Value Rating Type Atari part number
C24 470 µF 35 V Electrolytic, axial C070450-008
C36, C50 100 µF 16 V Electrolytic, axial C070499-004
C51, C72, C87 15 µF 25 V Tantalum C398069-001

A board with the video encoder therefore has 28 aluminium electrolytics and three tantalums.[1] exxos found the composite-sync coupling capacitor in the video circuit fitted the wrong way round: the voltage across it was reversed, about 3.9 V, a new part fitted to the board marking bulged within days, and turning the part round cured sync dropouts on his own Falcon. Measure the voltage across that capacitor before fitting its replacement.[3][2] The rest of the board is surface-mount ceramic, plus a 1000 pF mylar capacitor at C69 on the encoder boards and a 5–30 pF trimmer at C224 on the PAL boards.[1]

The Falcon's main board also has two TL497A switching regulators (U3, U27) and an LM7809 (U8).[1] The service guide's symptom checklist names the ±12 V DC-to-DC inverting supply for RS-232 faults and the +8 V regulator for missing DMA sound.[4]

Power supply

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Atari gives no capacitor list for the supply. exxos sells an upgrade kit for it; the kit list gives values but no designators. It replaces three 1000 µF parts with 1500 µF, the 33 µF 400 V reservoir with 47 µF 400 V, a 330 µF part with 680 µF, and two 47 µF and one 22 µF ripple-filter parts with 47 µF, and swaps the 1 A bridge rectifier for a 2 A part, whose pinout differs from the original. On an aged supply exxos measured spikes of about 600 mV on +5 V; after the recap the output varied by about 20 mV. He lists recapping the supply as a mandatory fix because spikes from an ageing supply can kill a Falcon.[5][2]

Replacement

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Disassembly follows Atari's section 4: seven screws hold the top case (four in the square holes, three in the round ones); the keyboard unplugs at the right front corner; nine screws hold the shield and speaker; the power supply has four corner screws and a harness at its right front corner; the memory board lifts out; three screws hold the shield and board assembly at the front; and six screws hold the upper shield to the board.[6]

  1. Photograph the board and note the polarity of every part before removing anything.
  2. Replace one capacitor at a time, observing polarity.
  3. Clean the pads with isopropyl alcohol and inspect every joint.
  4. Reassemble in reverse order. Atari recommends retesting the computer once it is back in its plastic case, to check that nothing shorts to the shield.[6]

See Recommended Tools, Capacitor Failure Symptoms, and Battery Explosion, Capacitor or Corrosion Damage if electrolyte has reached the board.

Checks afterwards

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Atari's power supply specification: +5 V at 1.5–7.0 A and +12 V at 0–0.2 A; line, load and cross regulation 5 % on +5 V and 10 % on +12 V; ripple and noise each 100 mV p-p; the +5 V output is set to 5.05 ± 0.1 V with a 4.0 A load.[7] The operator audio tests in Atari's diagnostic expect 4 V ± 0.2 V peak to peak at both audio outputs.[8]

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References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Atari Corporation, Atari Falcon030 Service Guide, C303062-001, 1 October 1992, Section 7, "Parts List and Assembly Drawings": main board variants and the parts unique to each (pp. 111–115), parts common to all boards (pp. 115–126). Hosted here as File:Atari Falcon030 Service Guide C303062-001.pdf. Source of every value, rating, designator and part number on this page.
  2. ↑ 2.0 2.1 2.2 exxos, "MANDATORY FIXES", exxos's Atari, Amiga & retro forum, 31 January 2019: item 1 (recap the supply), item 7 (Falcon bulk capacitance) and item 13 (Falcon composite-sync capacitor). Community source.
  3. ↑ exxos, "Falcon Csync video fault", exxos's Atari, Amiga & retro forum, 20 March 2019. Community source.
  4. ↑ Atari Corporation, Atari Falcon030 Service Guide, C303062-001, Section 5, "Symptom Checklist", pp. 104–105.
  5. ↑ exxos, "ATARI PSU REPAIR", The LaST Upgrade, part 6, sections "Falcon PSU" and "Falcon PSU upgrade kit", updated 2026. Kit seller's list and community measurements.
  6. ↑ 6.0 6.1 Atari Corporation, Atari Falcon030 Service Guide, C303062-001, Section 4, "Disassembly/Assembly", pp. 99–101.
  7. ↑ Atari Corporation, Atari Falcon030 Service Guide, C303062-001, Section 1.3, "Power Supply", pp. 4–5.
  8. ↑ Atari Corporation, Atari Falcon030 Service Guide, C303062-001, Section 3.6.2.2.1, audio tests, p. 85.


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