Yesico FL-420TX(T)P

General Impressions

A big heat sink makes the Yesico FL-420TX stand out

Yesico's FL-420TX (currently not available in the US), is another example of a fanless power supply, but at 420 watts of maximum power, it's also the most powerful of its type among all units tested here. The unit's large heat sink is on the back so it can conduct heat outside the PC case easily and effectively. The substantial heat this device can produce leads to another label that warns users to keep their mitts off lest they be burnt.

You'll find two LEDs on this device right next to the power switch: one that indicates device operation (green), the other that warns when a temperature threshold is exceeded (yellow).

Two LEDs provide status information

Yesico's power supplies employ the company's proprietary Thermal Management System, usually abbreviated as TMS. This makes it possible to use the power supply to manage fan operation throughout the PC when temperature thresholds are exceeded.