SGI Visual Workstation 540 Capacitor Replacement Guide
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No capacitor values have been published for the SGI Visual Workstation 540. SGI's owner's guide covers the parts an owner can replace, and it treats the power supply, the processor voltage regulator cards and the system board as complete units with no schematic or parts list.[1][2][3]
Where the power circuitry is
[edit | edit source]| Assembly | What SGI documents |
|---|---|
| Power supply | Top left of the case. Removed as a unit with four screws at the back, two connectors to the system board and the side-cover interlock cable.[1] The machine is rated at 838 W from the wall, 9 A maximum, power factor at least 0.98, peak inrush 45 A.[4] |
| Voltage regulator cards | Plug-in cards in brackets above and below the processor cage: one for the graphics, always fitted, and the others according to the number of processors, up to seven cards in all. SGI's remedy for a dead regulator is to replace the card.[2][3] |
| System board | Carries the Cobalt chipset, memory, PCI slots and the CR2032 battery.[5] SGI's remedy for a board fault is a replacement board.[3] |
The owner's guide gives the AC input ratings only.[4] The label on the supply in the 540 photographed by sgistuff.net gives SGI part number 060-0048-001, revision 3, date code 9942, made in the Philippines, with these outputs:[6]
| Output | Maximum current |
|---|---|
| +3.43 V | 44 A |
| +5.1 V | 37 A |
| +12 V | 32 A |
| −12 V | 0.55 A |
| +5 V standby | 1 A |
The label gives the continuous output as 587 W, with no more than 238 W combined from the +3.43 V and +5.1 V outputs.[6]
The 540's supply is not the 320's. SGI gives the 540 a 9 A maximum input at 100 to 120 V, against 4.7 A for the SGI Visual Workstation 320 on its 110 V setting.[4][7] The ATX conversion published on the SGI320 community site describes the 320's 24-pin main and 5-pin auxiliary connectors and does not cover the 540.[8]
What the photographs show
[edit | edit source]The published photographs of a 540 (sgistuff.net) show two groups of capacitors outside the power supply.[6]
- On the system board between the upper regulator connectors (J67, J75, J76) and the processor cage, a row of surface-mount aluminium can capacitors with a coloured band on the top, designated C268, C294, C301, C311, C317 and C323, with more of the same type at C224 and C226 to the left of the cage and in the space under the upper regulator brackets. The printed values on their tops cannot be read at the published resolution.
- Under the processor cage, where SGI fits the lower regulator cards with their components facing down,[9] rows of tall radial electrolytics in blue and black sleeves stand beside toroidal inductors.
No published photograph shows the inside of the power supply or a regulator card out of the machine.
Symptoms that point at capacitors
[edit | edit source]SGI's troubleshooting table lists a dead power supply, a dead voltage regulator and a failed system board as causes of a machine that will not power on, and a regulator card left in place for a processor slot that holds a terminator card as a cause of a continuously blinking LED with no picture.[3] None of these is specific to capacitors. Before suspecting them, work through SGI Visual Workstation 540 Troubleshooting Guide, which separates memory, processor, regulator and supply faults. For the signs of failed electrolytics in general (domed tops, electrolyte on the board, brown staining, a supply that will not start or cycles) see Capacitor Failure Symptoms.
Recording your own board's capacitors
[edit | edit source]Without a parts list, the board in front of you is the only reference. Before removing anything:
- Photograph each area of the system board, each regulator card and, if you open it, the power supply board, square on and in good light, so that the printing on the capacitor sleeves can be read.
- For every electrolytic, note the designator printed on the board beside it, the capacitance, the voltage rating, the temperature rating, the maker and series, the can diameter and height, and the polarity stripe.
- List any solid polymer capacitors separately from the wet aluminium electrolytics.
- Replace like for like: the same capacitance, the same or a higher voltage rating, at least the same temperature rating and a low-ESR series wherever the original is in a regulator or supply output, with a can that fits the space.
- Keep the list and photographs with the machine for the next repair.
Safety
[edit | edit source]The power supply runs from the mains, and the capacitors on its primary side can hold a dangerous charge after the plug is pulled. Unplug the machine, remove the supply, and discharge and measure the primary capacitors before touching anything on its board. See Recommended Tools for discharge tools and meters.
Related pages
[edit | edit source]- SGI Visual Workstation 540
- SGI Visual Workstation 540 General Maintenance
- SGI Visual Workstation 540 Troubleshooting Guide
- SGI Visual Workstation 540 Documentation
- SGI Visual Workstation 320 Capacitor Replacement Guide
- Capacitor Failure Symptoms
References
[edit | edit source]- ↑ 1.0 1.1 Silicon Graphics 540 Visual Workstation Owner's Guide (007-3882-001), "Replacing the Power Supply", pp. 120–128.
- ↑ 2.0 2.1 Silicon Graphics 540 Visual Workstation Owner's Guide (007-3882-001), chapter 6, "Processors and Voltage Regulators", pp. 102–118, Figure 6-1 (p. 103).
- ↑ 3.0 3.1 3.2 3.3 Silicon Graphics 540 Visual Workstation Owner's Guide (007-3882-001), Table 8-1, "Troubleshooting", pp. 141–142.
- ↑ 4.0 4.1 4.2 Silicon Graphics 540 Visual Workstation Owner's Guide (007-3882-001), Appendix A, Table A-4, "Power Specifications", p. 157.
- ↑ Silicon Graphics, Inc., Silicon Graphics 540 Visual Workstation Owner's Guide, 007-3882-001, 1999, Figure 2-6, "Interior View of the Silicon Graphics 540 Workstation", p. 23. Hosted as File:SGI Visual Workstation 540 Owner's Guide (007-3882-001).pdf.
- ↑ 6.0 6.1 6.2 Gerhard Lenerz, photographs "Visual Workstation 540 system board" and "Closeup of the Xeon CPUs", sgistuff.net, Visual Workstation 320/540, taken 13 December 2011. Retrieved 2026-10-21. Read from the full-size images: power supply label, capacitor designators, regulator card area. Hosted copy: File:SGI Visual Workstation 540 system board and power supply (sgistuff.net).jpg.
- ↑ Silicon Graphics, Inc., Silicon Graphics 320 Visual Workstation Owner's Guide, 007-3701-001, 1999, Table A-2, "AC Power", p. 99. Hosted as File:SGI Visual Workstation 320 Owner's Guide (007-3701-001).pdf.
- ↑ Milton Adamou, "PSU", SGI320 Visual Workstation site. Retrieved 2026-10-21. ATX conversion for the 320's main and auxiliary (J27) power connectors.
- ↑ Silicon Graphics 540 Visual Workstation Owner's Guide (007-3882-001), "Inserting Voltage Regulators", p. 109: cards below the primary processor go in with their components facing down.