I made this and used it sometimes ago, all parts are reused parts as long as it still functioning, inside the box are several parts that build up the recorder, an old PC power supply, an USB to IDE interface connector, a 80GB IDE HDD, a 5V relay and power cable.
Step 1: Modify the Usb to Ide Interface Converter
Break the interface converter cover to find out the red+ and black- power lines soldering points, solder two pieces of wire to extend the 5V power to the relay as shown in picture.
Step 2: Connect the Relay
The power lines extended from converter solder to the relay solenoid, solder the AC power line (live line) to the NO point of the relay, neutral line direct solder to the PC power supply AC input neutral point, and then solder a short wire from the COM point of the relay to the PC power supply AC input live point.
Step 3: Prepare the Pc Power Supply
This is an old ATX power supply, normally AC power is direct connected and switch it on/off from the PC mainboard, there is no PC control inhere, so I short circuited the green and black line from the ATX plug (the plug was removed), check the green wire at the bottom of the picture, when AC power is provided the power supply is switched on. The function of the relay is to switch on/off the power to the supply, the relay is to be triggered by the USB power that connected to the TV USB port, so the entire system does not consumed power only when TV is switched on.
Step 4: Record TV Programs
Connect the USB cable to the TV USB port, the HDD will be detected if everything okay, the HDD may need to be formatted for the first time use, refer to TV operation menu for details. This instructable only described how to reuse parts to build the recorder, if you really need to record TV programs and do not have the mentioned parts, just buy a PC External USB HDD is okay.