This part is a kind of semiconductor called FSP150-50LM.

Function of this product has 150 Watts Open Frame ATX Power Supply.

Manufacturers : Sparkle Power

Image and pinout :

Some of the text within the PDF file :

Sparkle Power Inc. A Leading Power Supply Manufacturer Web site: www.sparklepower.com FSP150-50LM (OPEN FRAME, RoHS Compliant) 150 Watts Open Frame ATX Power Supply Features    Specification  Complied with ATX12V standard Active Power Factor Correction (PFC) meet EN61000-3-2 Compatible with European Union Directive 2011/65/EU (Restriction on Hazardous Substances). Temperature Range: Storage & shipping: -20°C ~ +80°C. Operating: 0°C ~ 35°C (150W/35°C, 120W/50°C, 80W/60°C) A moderate air flow minimal of 5 CFM, is necessary for power supply to meet thermal requirement at full load condition.       Remote ON/OFF function Low ripple and noise. Output over voltage, short circuit, and over current protection 100% Hi-pot, ATE, and burn-in tested Re-settab [ ... ]

FSP150-50LM PDF Datasheet Download