Description
Newton NPS-400AB | ATX Computer Power Supply
Product Introduction
A workstation that will not boot, resets under load, or loses power intermittently may have a failing power supply—but replacing it with any unit labeled “400 W” is not a sound repair strategy. The Newton NPS-400AB is an internal ATX-style switching power supply associated with Fujitsu Siemens workstation hardware, including certain Celsius systems. Its job is to convert AC mains input into the regulated DC rails required by the motherboard, drives, and other installed components.
The published specification for the NPS-400AB B lists a 410 W rated output, with a maximum figure of 470 W appearing in some supplier listings. Input is specified as 100–240 VAC, 50/60 Hz, 8 A. Output-current limits differ by rail and revision, so total wattage alone is not enough to establish compatibility. Check the exact OEM part number, connector layout, and rail ratings against the original supply before installing a replacement.
NPS-400AB
Key Technical Specifications
- Manufacturer: Newton Power
- OEM association: Fujitsu Siemens Computers
- Model: NPS-400AB B
- OEM part number: S26113-E503-V50
- Power supply type: Internal switching power supply
- Form factor: ATX-style; verify physical dimensions and mounting points
- AC input voltage: 100–240 VAC
- Input frequency: 50/60 Hz
- Maximum input current: 8 A
- Rated output power: 410 W
- Advertised maximum power: Up to 470 W in some listings; verify the rating label and applicable operating conditions
- DC output rails: +3.3 V, +5 V, +12 V, −12 V, and +5 V standby, depending on the exact revision
- Cooling: Integrated fan
- Main connectors: 24-pin ATX and 12 V CPU power connections are reported for the B revision; verify all connector types and pin assignments
- Compatibility reference: Certain Fujitsu Celsius M460 workstation configurations
- Lifecycle status: Legacy component; current availability depends on independent suppliers
Published specifications identify the B revision as S26113-E503-V50. The A revision uses a different OEM part number, S26113-E481-V50. Confirm the full designation before purchasing.
Application Scenarios & Pain Points
Scenario A — Recovering an older engineering workstation
A legacy workstation used for CAD, machine programming, or industrial configuration software suddenly stops powering on. If diagnostics point to a failed PSU, the NPS-400AB B may be a suitable replacement for a compatible Fujitsu Celsius configuration. Matching the OEM part number and connector layout helps avoid an unnecessary motherboard replacement.
Scenario B — Random resets during CPU or graphics load
- Symptom: The system runs at idle but restarts when processing demanding workloads.
- Potential cause: A failing power supply, degraded components, or an overloaded output rail.
- Recommended action: Measure the supply under appropriate load and compare the individual rail ratings with the original specification. A nominal 410 W rating does not guarantee sufficient current on every rail.
Scenario C — Replacing an obsolete PSU without changing the platform
When the original workstation must remain in service, retaining the existing motherboard, storage, and software environment may reduce migration effort. The NPS-400AB can support this approach when the replacement matches the exact system configuration. Check mounting dimensions, cooling airflow, and cable routing before installation.
Scenario D — Procurement for maintenance stock
For facilities supporting older engineering computers, an inspected spare can shorten repair lead times. Before accepting a unit, record its revision, OEM part number, physical condition, and load-test results. Establishing these acceptance criteria is more useful than buying solely on the advertised wattage.
QA & Live Testing SOP
A replacement power supply should be evaluated as an electrical component, not accepted on appearance alone.
- Origin verification: Inspect the Newton/Fujitsu identification label and compare the complete model and part number against the required unit.
- Physical inspection: Check the housing, fan, cable insulation, connectors, and mounting points for damage or unauthorized modifications.
- Electrical testing: A qualified technician should measure the DC output rails using suitable equipment and verify that the outputs remain within the applicable specifications.
- Load testing: Request documented testing under an appropriate load, including checks for voltage stability and excessive ripple.
- Fan operation: Verify fan startup and operation during the test procedure.
- Protection checks: Confirm available overcurrent, overvoltage, and short-circuit protection specifications from the applicable documentation; do not assume every protection feature is present without evidence.
- Packaging: Protect the PSU and connectors during transit, using suitable antistatic and mechanical protection where appropriate.
These are recommended inspection procedures, not a claim that the specific unit in the supplied listing has passed them. Ask the seller for actual test results and warranty terms.
Field Engineer’s Pitfall Guide
- ❗ Do not confuse NPS-400AB A with NPS-400AB B. The B version is associated with OEM part number S26113-E503-V50, while the A version is associated with S26113-E481-V50. Match the original label before ordering. Similar model names do not establish electrical interchangeability.
Computer, server power supply
- ❗ Never judge compatibility by wattage alone. A replacement rated at 410 W may still be unsuitable if its individual rail-current limits, connector pinout, or startup behavior differ from the original. Verify the +12 V, +5 V, and +3.3 V requirements against the workstation’s specifications.
- ❗ Check the complete connector arrangement before installation. A 24-pin motherboard connector does not prove that the CPU power connector, peripheral leads, and chassis mounting dimensions will match. Disconnect AC power before replacing the PSU, and never open the power supply housing—internal capacitors can retain hazardous voltage.
Intent-Driven FAQ
Q1: Is the Newton NPS-400AB compatible with my Fujitsu Celsius workstation?
It is associated with certain Fujitsu Celsius systems, including the M460. Compatibility depends on the exact workstation model, PSU revision, connector arrangement, and electrical requirements. Compare the original unit’s OEM part number with the replacement before ordering.
Q2: What is the output wattage of the NPS-400AB?
The NPS-400AB B is commonly specified at 410 W rated output. Some listings also advertise a maximum of 470 W. Treat these figures separately and verify the actual label and operating conditions rather than assuming 470 W is continuously available.
Q3: What is the input voltage range for the Newton NPS-400AB?
Published specifications for the B revision list 100–240 VAC, 50/60 Hz, 8 A. Confirm the label on the exact unit before installation, particularly when servicing equipment in a different electrical environment.
Q4: Can I replace an NPS-400AB A with an NPS-400AB B?
Do not assume so. The two revisions have different OEM part numbers, and matching the family designation alone does not prove compatibility. Verify output-rail ratings, connectors, mounting dimensions, and the workstation manufacturer’s approved replacement information before making the substitution.
Computer, server power supply
Q5: Is the Newton NPS-400AB still available?
Legacy replacement units appear through independent industrial and computer-parts suppliers. Availability and condition vary. A listing may describe a unit as new, open-box, or refurbished, so request confirmation of its actual condition and whether it has been electrically tested.
Q6: How do I know whether the NPS-400AB is causing random shutdowns?
Start by checking system event logs, temperatures, motherboard diagnostics, and the power supply’s output under load. A failing PSU is one possible cause, but overheating, motherboard faults, memory errors, and overloaded rails can produce similar symptoms. Use a qualified technician and appropriate test equipment to isolate the fault.
Q7: What warranty should I expect when buying a replacement NPS-400AB?
Warranty coverage depends on the supplier and the condition of the unit. Obtain the coverage period, return policy, and terms for electrical failure in writing. Do not assume that an independent seller’s warranty is equivalent to an original manufacturer’s warranty.
Final procurement recommendation: The Newton NPS-400AB is best sourced by matching the full OEM part number, verifying rail-level electrical specifications, and confirming the connector layout. For legacy workstation maintenance, those details matter more than the headline wattage or a seller’s “compatible” description.
