Power Macintosh 7200 Capacitor Replacement Guide
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The Power Macintosh 7200 logic board, 820-0583-A, uses surface-mount polarised capacitors. Console5 publishes a list of 37 positions for this board, in three values: 100 µF 6.3 V, 10 µF 16 V and 47 µF 16 V.[1] Apple's logic board schematic for PCB 820-0583 shows all 37 positions: 33 have the value Console5 gives and four do not. The bill of materials bound with the schematic describes the 100 µF, 10 µF and 47 µF parts as surface-mount electrolytics, with a separate group of tantalum capacitors.[2]
Apple's Service Source treats the logic board and the power supply as single parts and gives no component values.[3]
Logic board capacitors
[edit | edit source]| Position | Console5 | Apple schematic (sheet) | Rail on the schematic |
|---|---|---|---|
| C?? | 100 µF 6 V | C8: 100 µF 6.3 V (21) | Audio line out |
| C17 | 100 µF 6 V | 100 µF 6.3 V (21) | Audio line out |
| C18 | 10 µF 16 V | 10 µF 16 V (21) | Microphone/line in |
| C27 | 100 µF 6 V | 100 µF 6.3 V (21) | Audio line out |
| C28 | 10 µF 16 V | 10 µF 16 V (21) | Microphone/line in |
| C29 | 10 µF 16 V | 10 µF 16 V (21) | Microphone/line in |
| C30 | 47 µF 16 V | 47 µF 16 V (19) | +5 V through fuse F1 to the Ethernet port |
| C31 | 10 µF 16 V | 10 µF 16 V (21) | Speaker amplifier supply |
| C36 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C37 | 47 µF 16 V | 47 µF 16 V (22) | Cuda supply |
| C44 | 47 µF 16 V | 47 µF 16 V (14) | Clock generator analogue supply |
| C53 | 10 µF 16 V | 10 µF 16 V (17) | Curio (Ethernet, SCSI, serial) analogue supply |
| C56 | 100 µF 6 V | 47 µF 16 V (4) | Processor I/O supply |
| C58 | 47 µF 16 V | 47 µF 16 V (15) | +3.3 V at the PCI slots |
| C62 | 100 µF 6 V | 100 µF 6.3 V (14) | +3.3 V clock supply |
| C63 | 100 µF 6 V | 47 µF 16 V (4) | Processor core supply |
| C64 | 10 µF 16 V | 10 µF 16 V (4) | Processor core supply |
| C67 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C68 | 100 µF 6 V | 47 µF 16 V (4) | Processor I/O supply |
| C69 | 10 µF 16 V | 10 µF 16 V (4) | Processor I/O supply |
| C71 | 47 µF 16 V | 47 µF 16 V (22) | +5 V at the power connector |
| C76 | 47 µF 16 V | 47 µF 16 V (22) | Trickle 5 V |
| C78 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C84 | 100 µF 6 V | 47 µF 16 V (4) | Processor core supply |
| C85 | 47 µF 16 V | 47 µF 16 V (22) | +12 V |
| C87 | 47 µF 16 V | 47 µF 16 V (22) | −12 V (positive end to ground) |
| C89 | 47 µF 16 V | 47 µF 16 V (12) | +5 V at the DIMM slots |
| C90 | 47 µF 16 V | 47 µF 16 V (12) | +5 V at the DIMM slots |
| C91 | 47 µF 16 V | 47 µF 16 V (12) | +5 V at the DIMM slots |
| C92 | 47 µF 16 V | 47 µF 16 V (12) | +5 V at the DIMM slots |
| C94 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C97 | 10 µF 16 V | 10 µF 16 V (13) | Video DAC supply |
| C99 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C100 | 10 µF 16 V | 10 µF 16 V (13) | Video DAC +5 V |
| C118 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C119 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
| C122 | 47 µF 16 V | 47 µF 16 V (22) | +5 V bulk |
Console5 prints the first position as "C??". On the schematic the third 100 µF 6.3 V audio output capacitor, beside C17 and C27, is C8.[1][2]
The two sources disagree on C56, C63, C68 and C84: Console5 lists 100 µF 6 V, while the drawing shows 47 µF 16 V on the processor core and I/O supplies, in a group marked "Place near corners of 601 on top side". The drawing is a pre-production document, so the production board may differ; read the marking on each part before ordering. The drawing also shows two further 47 µF 16 V capacitors on the processor core supply, C51 and C88, which Console5 does not list, a 10 µF 16 V position at C75 marked "NO STUFF" (not fitted), and six 1 µF 10 V capacitors coupling the audio inputs (C16, C22, C26, C32, C33, C34).[2]
The bill of materials at the back of the schematic is from the EVT2 pre-production build, dated 31 March 1995. It lists nine 10 µF 16 V, four 100 µF 6.3 V and nineteen 47 µF 16 V surface-mount electrolytics, plus fourteen tantalum capacitors (six 1 µF 10 V, one 10 µF 16 V, five 47 µF 16 V and two 0.47 µF 25 V). The drawing sheets also have four 100 µF 6.3 V capacitors: C8, C17, C27 and C62. The bill of materials' designators do not match the drawing sheets, so use it only for the types and values, not for positions.[2]
Inspection
[edit | edit source]Swing up the internal chassis to reach the board, or remove the board as described on Power Macintosh 7200 General Maintenance. Look for:
- electrolyte residue or corrosion round the capacitor pads
- bulging or leaking cans
- damage near the clock battery holder at the front left of the board; a leaking lithium cell leaves acidic residue (see Battery Explosion, Capacitor or Corrosion Damage)
Capacitor Failure Symptoms describes what failing parts look like.
Replacement
[edit | edit source]- Photograph the board and record the value, voltage and polarity of every part before removing anything.
- Remove each capacitor with hot air or two irons, without lifting the pads. Clean away any electrolyte and corrosion with isopropyl alcohol.
- Fit parts of the same capacitance and at least the same voltage rating, observing polarity. C87 sits on the −12 V rail with its positive end to ground.[2] On an aluminium electrolytic the marked side is negative; on a tantalum the stripe marks the positive end.
- Do not fit capacitors to empty pads. The drawing marks some positions "NO STUFF", C75 among them.[2] On a 7300 logic board, which is a different design, an owner who added capacitors to empty pads found the machine would no longer start.[4]
- Check each new part for a short to ground before the first power-up.
Power supply
[edit | edit source]Apple gives the same service part, 661-0920, for the 7200 supply as for the 7500 and 7600 supplies.[3][5] The label carries Apple's assembly number 614-0039, which does not identify the maker: the supply taken from one 7200 was a Delta DPS-150GB, and owners have found ASTEC-made 614-0039 supplies in the 7500.[6][7] Apple gives no capacitor values for it. Owners who have recapped these supplies, one of them with a Console5 kit, report that:[7]
- the large capacitors are glued to the board with brittle white adhesive; desolder each one fully, rock it free and leave the rest of the glue where it does not get in the way
- on the Delta DPS-150GB from a 7600, removing the glue round C2 pulled resistor R41 off its leads; R41 on a working supply measured 838.6 kΩ, and an 845 kΩ 1 % resistor restored the repaired supply. These designators are the Delta board's; check an ASTEC supply against its own markings
- replacement capacitors are nearly always smaller than the originals, so they fit
Record every value from the board before removing anything. The primary-side capacitors charge to mains-derived voltage; discharge them and confirm with a meter before touching the primary side. Check the 115/230 V switch before the supply goes back in.[8]
Related pages
[edit | edit source]- Power Macintosh 7200
- Power Macintosh 7200 General Maintenance
- Power Macintosh 7200 Troubleshooting
- Power Macintosh 7500 Capacitor Replacement Guide
- Capacitor Failure Symptoms
- Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 Console5 Tech Wiki, "Power Macintosh", section "7200: 820-0583-A" (community list read from boards, not taken from Apple documents; accessed 2 October 2026). Console5 sells the set as a tantalum kit.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Apple Computer, Main Logic Board Schematic, PCB 820-0583 (Catalyst). Drawing sheets 4, 12, 13, 14, 15, 17, 19, 21 and 22 (PDF page numbers match the sheet numbers); bill of materials "catalyst-evt2-v11c.bom", dated 31 March 1995 on PDF p. 28, capacitor lines on PDF p. 29. Hosted as File:Power Macintosh 7200 Catalyst logic board schematic (820-0583).pdf; see Power Macintosh 7200 Logic Board Schematic.
- ↑ 3.0 3.1 Apple Computer, Service Source: Power Macintosh 7200 Series/WS 7250 (1996), exploded view, PDF p. 157: logic boards 661-0979, 661-1000, 661-1059, 661-1080; power supply 661-0920. File:Powermac_7200_series.pdf; see Power Macintosh 7200 Series/WS 7250 Service Source.
- ↑ 68k Macintosh Liberation Army forum, "Power Mac 7300 issues post tantalum" (2020): after a logic board recap in which two extra capacitors were fitted to empty pads and later removed, the fan and LED came on but the machine gave no chime and no video.
- ↑ Apple Computer, Service Source: Power Macintosh 7300/7500/7600 & WS 7350 (1997), exploded view, PDF p. 170: power supply 661-0920, marked with an asterisk for "refer to parts list". File:Pm7300.7500.7600.ws7350.pdf; see Power Macintosh 7300/ 7500/7600 & WS 7350 Service Source.
- ↑ modelrail.otenko, "Power Mac 7200: Power Supply": Delta DPS-150GB A, Apple 614-0039, removed from a 7200; four screws hold the lid; the fan's two-wire cable plugs into the supply's circuit board.
- ↑ 7.0 7.1 68k Macintosh Liberation Army forum, "Need Resistor Value from PowerMac 7600 Power Supply Delta DPS-150GB" (2025–2026): 614-0039 supplies from a 7500 (ASTEC) and a 7600 (Delta); Console5 recap kit; capacitors glued with white adhesive; R41 845 kΩ.
- ↑ Apple Computer, Service Source: Power Macintosh 7200 Series/WS 7250 (1996), Take Apart, PDF pp. 96 and 103: set the voltage switch on the back of the supply correctly (115 V in the US) when replacing it. File:Powermac_7200_series.pdf.