Introduction

FSP (also known as Fortron-Source) are one of the most experienced computer PSU manufacturers on the planet. Even though they usually keep a low profile and aren't particularly aggressive in the retail market, FSP recently released a very wide range of self-branded retail products. Today we will have a look at one of the most interesting products they released, the Zen 400W Passive PSU.

Passive units are very popular among HTPC enthusiasts who are trying to build capable but entirely silent running computers. We will see if the Zen can deliver performance capable of appeasing HTPC enthusiasts in this review.

Manufacturer's Features and Specifications

• Low ripple & noise
• Over voltage protection
• Short circuit protection
• Fanless design (no fan noise)
• High efficiency 
• 100% burn-in test
• MTBF: 100K hours at 25°C
• Safety:    
  GNF: UL, Nemko, CB, CE, BSMI, FCC, CCC      
  TNF: UL, Nemko, CB, CE, VDE, FCC

Input Specifications
• Voltage:	110-240 VAC
• Frequency:	47 ~ 63 Hz
• Input current:	3.5A / 2A
Output Specifications
• Over-voltage protection:	+5V, +3.3V, +12V1, +12V2
• Over-current protection:	+5V, +3.3V, +12V1, +12V2
• Remote ON/OFF control:	The power supply shall accept a logic collector level which will disable / enable all output voltage (excluding +5V standby).
• Power good signal:	turn-on delay 100 ms to 500 ms
General Specifications
• Efficiency:	80% mini. (GNF), 85% mini. (TNF)
• Hold-up time:	17 mS mini.
Environmental Specifications
• Operating conditions:	Ambient temperature 0°C~30°C, 5~95% RH
• Storage and   shipping conditions:	Ambient temperature -20°C~80°C, 5~95% RH

Model	Watts	Outputs
		+3.3V	+5V	+12V1	+12V2	+12V3	+12V4	-12V	+5Vsb
FSP400-60TNF	400W	20A	14A	14A	13A	-	-	0.5A	2.5A

Packaging and Bundle

The Zen is supplied in a sturdy cardboard box with a small window at the front, showing the bottom part of the product. The box is simple but well designed and the most important specifications of the product can be found at the rear. Inside the box you will find a basic manual, an AC power cable, the necessary mounting screws, a few black cable management straps and a sticker with the company logo.