Power Macintosh 7200 Capacitor Replacement Guide
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The Power Macintosh 7200 logic board, 820-0583-A, uses surface-mount polarised capacitors of three values: 100 µF 6.3 V, 10 µF 16 V and 47 µF 16 V. Console5 publishes a list of 37 positions for this board.[1] Apple's logic board schematic for PCB 820-0583 confirms most of them by designator and value, and the bill of materials bound with it 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 | not on the sheets checked | – |
| 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) | SCSI terminator power |
| 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 | not on the sheets checked | – |
| C53 | 10 µF 16 V | not on the sheets checked | – |
| C56 | 100 µF 6 V | 47 µF 16 V (4) | Processor I/O supply |
| C58 | 47 µF 16 V | not on the sheets checked | – |
| C62 | 100 µF 6 V | not on the sheets checked | – |
| C63 | 100 µF 6 V | 47 µF 16 V (4) | Processor core supply |
| C64 | 10 µF 16 V | 10 µF 16 V (4) | Processor 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 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 | not on the sheets checked | – |
| 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 | not on the sheets checked | – |
| 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). Its 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 board design carries unpopulated positions; an owner who added capacitors to empty pads on the related 7300 board found it would no longer start.[4]
- Check each new part for a short to ground before the first power-up.
Power supply
[edit | edit source]The 7200 supply is Apple 614-0039, made by Delta (DPS-150GB) and also found with an ASTEC label, and shared with the 7500 and 7600.[5][6] No capacitor list for it has been published. Owners who have recapped it report that:[6]
- 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
- removing the glue round C2 pulled resistor R41 off its leads on one board; on a working supply R41 measured 838.6 kΩ, and an 845 kΩ 1 % resistor restored the repaired supply
- 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.
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" (secondary source; read 2 October 2026). Console5 sells the set as a tantalum kit.
- ↑ 2.0 2.1 2.2 2.3 2.4 Apple Computer, Main Logic Board Schematic, PCB 820-0583 (Catalyst). Drawing sheets 4, 12, 13, 19, 21 and 22; bill of materials "catalyst-evt2-v11c.bom" (31 March 1995), PDF p. 29. Hosted as File:Power Macintosh 7200 Catalyst logic board schematic (820-0583).pdf; see Power Macintosh 7200 Logic Board Schematic.
- ↑ 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.
- ↑ 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 plugs into the board with a two-wire connector.
- ↑ 6.0 6.1 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.