The heart of this sub-circuit is the TNY279PN Power Integrations IC (an 18W off-line switcher chip). It integrates a high-voltage power MOSFET and a controller onto a single die.
The largest capacitor on the board, crucial for holding the main DC voltage.
When using the schematic top alongside the physical layout, refer to this generic pin mapping:
When troubleshooting with a multimeter, focus on these top-side areas: TNY279PN IC No standby voltage (0V on Purple/Green) Primary 1-ohm Resistor Burnt; often fails with TNY279PN Secondary Output Diodes Shorted; PSU clicks or fails to start Secondary Capacitors Bulging or high ESR; flickering output 4. Tips for Repair ps42419ha schematic top
While the full schematic is not publicly available, a partial pinout listing has been extracted from a National Semiconductor Local Area Networks databook and confirmed against the PS-4241-9HA’s 24-pin connector.
While proprietary OEM schematics for HP power supplies are closely guarded, the PS-4241-9HA
: Implements an active boost topology that aligns input current with voltage phases. This configuration achieves an exceptional 0.99 Power Factor (PF) under full load, minimizing wasted reactive power. The heart of this sub-circuit is the TNY279PN
If you have the physical component and are trying to solder or trace connections:
High-side IGBTs require a gate voltage referenced to their emitter (the phase output), which floats up and down. The schematic top shows this clever trick:
High-current Schottky diodes or synchronous rectification MOSFETs drop the high-frequency AC down to clean DC. A array of low-ESR electrolytic capacitors smooth out ripple currents. When using the schematic top alongside the physical
Outputs are distributed via specialized pinouts—including a 6-pin main connector and dedicated auxiliary lines—rather than a standard ATX 24-pin block. Common Failure Points & Repair Diagnostics Because the HP PS-4241-9HA
I will structure the article as follows:
: Primarily provides 12V output. Unlike standard ATX power supplies, the 3.3V and 5V conversions often happen on the HP motherboard itself rather than inside the PSU. Common Failure Points & Repair Components