SCART - Practical Considerations

Practical Considerations

Nearly all DVD players with SCART sockets output RGB video, which offers far superior picture quality to typical composite signals. However, many players do not have RGB output turned on by default, instead defaulting to composite video — RGB often has to be set manually in the player's setup menu or via switches on the back of the player.

The Nintendo GameCube†, Wii†, Dreamcast, PlayStation, PlayStation 2, PlayStation 3, Xbox and Xbox 360 can output RGB, component video, S-Video, or composite video. These consoles come with the standard composite video connector, but the manufacturers and third parties sell connectors for component video hookup and for RGB SCART hookup. Where the Nintendo GameCube and Xbox automatically switch to the proper mode, the PlayStation 2 must be told via a selection in the system menu whether it is to use YP_BP_R or RGB video. Also, some versions of legacy consoles such as Sega's Mega Drive (Genesis) and Nintendo's SNES and Nintendo 64 (modified NTSC and early French SECAM versions only) are capable of outputting RGB signals.

Many older home computers (Amstrad CPC, later ZX Spectrum models, Commodore Amiga, Atari ST, BBC Micro and Acorn Archimedes, etc.) output RGB with composite sync suitable for SCART use, but most used varying non-standard DIN plugs. Standard-resolution arcade monitors use RGB signals with a composite sync, which is SCART-compatible.

Maximum SCART cable length is estimated to be about 10 to 15 metres without amplification.

Due to the relatively high signal voltages used in SCART, "hot plugging" (connecting or disconnecting devices while they are on) is not recommended. Although there is no risk of personal injury, there is the possibility of damaging electronics within the devices if the connector is inserted improperly. Also, since many TV sets are Class II (double-insulated) rather than being directly connected to earth, the large exposed shield on the SCART connector will be held at approximately half mains voltage if it is plugged into a powered TV with the other end unplugged. If the cable is then plugged into an earthed device with a metal case, inadvertent contact with the SCART cable shield while the earthed device is touched with the other hand can cause a painful (though not dangerous) electric shock. For this reason the device end of the cable should always be plugged in first and the TV end plugged in last.

Quality differences exist in SCART cables. While a proper SCART cable uses miniature coax cables for the video signals, cheap SCART cables often use plain wires for all signals, resulting in a loss of image quality and greatly reducing the maximum cable length. A common problem is that a TV outputs a composite video signal from its internal tuner, and this is induced or cross-talked onto an incoming video signal due to inadequate or non-existent screening on a cheap SCART cable; the result is ghostly images or shimmering superimposed on the incoming signal. To non-destructively verify if a SCART cable uses coax cables, one can unscrew the strain relief at the SCART connector and fold open the plastic shell.

Using higher-quality cables such as those with ribbon cords that have properly shielded coax cables inside might help in reducing a 'ghosting' effect, but it does not always completely eliminate it due to various factors. A more permanent method is to remove pin 19 from the SCART plug that is put into the TV. Pin 19 is Video Out, and removing it prevents a signal from being broadcast by the TV into the cable in the first place, so it cannot cross-talk with the incoming signal.