D10-240p1a Schematic ((link)) May 2026

The HP D10-240P1A is a specialized 240W Power Supply Unit (PSU) designed for HP’s Small Form Factor (SFF) business desktops, including the Elite 8000, 8100, 8200, and 8300 series. Unlike standard ATX power supplies, this model uses a proprietary architecture that requires specific pinouts for diagnostic testing and repair. Technical Specifications

The D10-240P1A is engineered for high efficiency, often carrying an 80 PLUS certification. Wattage: 240 Watts. Input: 100-240V ~ 4A, 50-60Hz. DC Output: Primarily 12V rails (12Vmain and 12Vcpu). Form Factor: Slim SFF (Proprietary HP). Connectors: (1) 6-Pin Main Power Connector. (1) 4-Pin ATX +12V CPU Connector. (1) Slim 6-pin auxiliary/special connector. Understanding the Schematic and Pinout

Because the D10-240P1A uses a proprietary 6-pin main connector instead of the standard 24-pin ATX, traditional PSU testers will not work without an adapter.

The Lite-On D10-240P1A is a 240W, 80 Plus Gold internal PSU used in HP ProDesk 600 G1 and EliteDesk 800 G1 SFF computers. While official schematics for this 6-pin proprietary unit are not publicly released, it typically features active PFC and synchronous rectification, with common failure points including the main fuse, standby rails, and startup capacitors.

The HP D10-240P1A is a specialized 240W Power Supply Unit (PSU) frequently found in HP’s Small Form Factor (SFF) desktop lines, including the HP Elite 8000, 8100, 8200, and 8300 series. Because these units use proprietary connectors rather than the standard 24-pin ATX layout, finding a schematic or repair guide is crucial for technicians looking to restore older systems. Core Specifications of the D10-240P1A D10-240p1a Schematic

This unit is a high-efficiency Switching Mode Power Supply (SMPS) designed for constant 12V output to the motherboard. Max Output Power: 240W Input Voltage: 100V–240V AC (Auto-switching)

Efficiency Rating: Often carries an 80 Plus Gold or similar high-efficiency certification Form Factor: SFF (Small Form Factor) Connectors: (1) 6-Pin main power connector (1) 4-Pin ATX +12V CPU power connector

(1) Slim 6-pin auxiliary connector for specific peripheral requirements D10-240P1A Circuit Architecture

While a complete proprietary schematic is rarely released by HP, the D10-240P1A follows a standard high-efficiency SMPS architecture: The HP D10-240P1A is a specialized 240W Power

The D10-240P1A is a 240W proprietary switching power supply (SMPS) manufactured by HP (often under the Lite-On or Delta brands) for its small form factor (SFF) business desktops, such as the Elite 8000, 8100, 8200, and 8300 series.

Because this is a proprietary OEM unit, a complete factory schematic is not publicly released, but technical teardowns and reverse-engineering reveal the following design characteristics: Circuit Design & Architecture

Topology: It uses an active Power Factor Correction (PFC) front-end followed by a standard switching stage to convert 100–240V AC to DC rails.

Voltage Rails: Unlike standard ATX power supplies, this unit provides a primary 12V output. The conversion to 5V and 3.3V is typically handled by DC-to-DC converters on the HP motherboard itself. Stability : Phase margin, oscillation tendencies

Efficiency: Certified under the 80 Plus Gold or Silver standards (depending on the revision), achieving over 90% efficiency at 50% load. Pinout and Connectors The D10-240P1A features a non-standard connector layout: Main Connector (6-Pin): Powers the motherboard. P2 Connector (4-Pin): Dedicated +12V CPU power.

P3 Connector (Slim 6-Pin): Often a specialized auxiliary or fan control connector.

Standby Voltage: It includes a 12Vsb (standby) rail rated at approximately 1.3A to keep the system ready for wake-on-LAN or power button signals. Common Review Points for Repair

D10-240p1a Schematic — Overview, Components, and Troubleshooting

3.3. Performance Metrics

Stability: Phase margin, oscillation tendencies.
Efficiency: Power dissipation in regulators.
Noise: Signal-to-noise ratio (SNR) in amplification stages.

4.3. Optimization Strategies

Component Swap: Replace standard diodes with Schottky diodes to reduce forward voltage drop (from 0.7 V to 0.3 V).
Decoupling Capacitors: Add 100 nF ceramic capacitors at supply rails to mitigate high-frequency noise.
Feedback Resistor Network: Adjust resistor values (R1 = 10 kΩ, R2 = 1 kΩ) to balance gain and stability.

Symptom C: Unit Shuts Down Immediately Under Load

Current sense resistor: On the primary schematic, locate the resistor(s) between MOSFET source and GND. Measure its resistance. A shifted value (usually from 0.22Ω to 0.5Ω) will trigger overcurrent protection too early.
Output capacitors: ESR test or simply replace all 2-4 large output caps (1000-2200µF, 35V). High ESR causes the control loop to oscillate under load.

Method 2: Reverse Engineering Communities

Electronics Repair Forums: EEVblog, Badcaps.net, Electro-Tech-Online. Search for threads with "D10-240p1a" or "240W 24V power supply schematic". Dozens of users have traced these units.
GitHub: Believe it or not, some hobbyists upload reverse-engineered KiCad or PDF schematics for common PSUs. Search D10-240p1a filetype:pdf using a custom search engine.

3.1. Schematic Deconstruction

Assuming the D10-240p1a schematic includes:

Operational Amplifier (e.g., LM741) for signal amplification.
Passive Components: Resistors (1–10 kΩ), electrolytic capacitors (10–100 µF), and coupling capacitors (0.1–1 µF).
Voltage Regulator (e.g., 7805) to stabilize DC supply.
Semiconductor Diodes: For rectification or protection.

Symptom A: "Dead" – No Output, No LED, Fuse Intact

Measure bulk capacitor voltage: Should be ~340V DC. If 0V, check AC input, fuse, thermistor, and bridge rectifier (per schematic).
Check VCC on PWM IC: Typically 12-18V. If 0V, the startup resistor (from bulk cap to VCC pin) is likely open. Replace it. (Schematic shows this as a high-value resistor, e.g., 150kΩ/2W).
If VCC is present but oscillating (e.g., 8V-15V cycling): Auxiliary winding or its filter capacitor is dead.