[ POWER CONVERSION // IDENTIFIED MODEL ]
IBM PS/2 Model 50 (8550) PSU (90X9527 / Astec AA13621)
IBM PS/2 8550 Model 50 supply, IBM P/N 90X9527 / FRU 90X9366, Astec AA13621. This entry covers the specific model or bounded historical system assembly identified here; suffixes and supplier revisions are not presumed equivalent.
HIGH-VOLTAGE SAFETY: Disconnect mains before external inspection. Never open a PSU. Internal capacitors can retain dangerous charge after disconnection. Do not probe or repair its interior; use qualified service or replace it.
Model-specific ratings & fit
| Manufacturer identity | IBM PS/2 8550 Model 50 supply, IBM P/N 90X9527 / FRU 90X9366, Astec AA13621 |
|---|---|
| Form factor / generation | IBM PS/2 proprietary internal supply, 1987–1990 generation |
| AC input | 100–125 V AC 3 A or 200–240 V AC 1.5 A, 50/60 Hz; verify selector and label. |
| DC output | 94 W nominal; +5 V 7.6 A, +12 V 0.35 A, −12 V 0.41 A per 8550 supply reference; exact assembly label controls. |
| Dimensions / mounting | 8550 internal chassis-specific supply; requires PS/2 Model 50 mounting/airflow arrangement. |
| Connectors | Proprietary PS/2 50-pin system connector plus chassis drive harness; not AT/ATX. |
| Revision distinctions | IBM/Astec assembly and FRU identifiers matter; 8570/other PS/2 models use different supplies even if similar connectors are seen. |
Compatibility & safe handling
- Verify full model, suffix, region and revision using the actual unit nameplate and matching manufacturer manual. Wattage and plug shape alone do not establish compatibility.
- Check AC input range, rail and combined output limits, derating, signaling/pinout, cooling direction, mounting and system qualification before installation.
- PSU modular-side cables are model-specific. Never reuse an unapproved lead; a matching plug can carry a different pinout.
- Server hot-plug is permitted only in qualified host configurations and under the host’s documented redundancy/live-service procedure.
- Never open or internally probe the supply. Retire damaged, wet, burnt, corroded, modified or unidentified units.
Revision & archival notes
IBM/Astec assembly and FRU identifiers matter; 8570/other PS/2 models use different supplies even if similar connectors are seen.
IBM PS/2 Model 50 technical-reference information archived with supply/FRU data; verify observed label against the IBM manual. Preserve source revision and part identity.
Photograph the full nameplate, model/FRU, supplier, revision/date code, line selector, cable ends, mounting orientation and source-document issue. Keep observed label data separate from test results.
Manufacturer or primary references
- IBM PS/2 Model 50 (8550) PSU (90X9527 / Astec AA13621) — manufacturer/product or primary technical referenceIBM PS/2 8550 Model 50 supply, IBM P/N 90X9527 / FRU 90X9366, Astec AA13621. Check the exact revision, region and system support information.
- Intel ATX / ATX12V Power Supply Design GuideReference for desktop ATX context only. Proprietary historical and hot-swap server outputs are not made interchangeable by ATX standards.
The specific PSU nameplate and corresponding model/service documentation remain controlling.