Re: Scart Switching XBOX and Gamecube via Tivo - Problem?

[Keith Doxey <ukha@xxxxxxx>]

Quoting steve@xxxxxxx:

> I have finally been press-ganged into getting an xbox by Mr McCall
> and have connected it up like this...
>
> My Xbox and Gamecube are plugged into a SCART multi box which is
> then plugged into the AUX socket on the Tivo.
>
> It all works fine, if I turn on the xbox the TV auto switches to it
> and the same goes for the Gamecube...
>
> But...
>
> When the Gamecube is off and the XBOX is on the power light on the
> cube lights up!
>
> Is this likely to cause me any problems?
>
> I'm wondering if the light is just a symptom of something more
> serious.
>

Hi Steve,

All the SCART switchboxes I have used DO NOT switch ALL the lines.

Of the 21 pins (actually 20 + Shield), 8 of them are ground and are all
tied
together.

The switchboxes tend NOT to switch Pin 8.
What they do is one of two things.

1. Cheapskate method

Common all Pin 8's together with diodes

In 1 ----->----
In 2 ----->---------
In 3 ----->----

Which means any of the inputs being high will drive the output high.

2. Really Cheapskate method

Connect all Pin 8's together
In 1 ---------
In 2 --------------
In 3 ---------

Which means any of the inputs being high will drive the output high but
does
not provide isolation between them and relies on the fact that the Pin 8
output
is usually switched by a transisitor ( effectively providing the diode
within
the source equipment) and/or current limited by a resistor within the
source
equipment.

It sounds like your switchbox uses method 2 and the Xbox Pin8 is feeding
back
to the Gamecube. The Gamecube *MAY* have its power LED connected to the
pin8
output which is why it is lighting up and is almost certainly harmless if
that
is the case, BUT, it maybe that the entire Game Cube is being powered up
from
the Xbox power supply which could possibly overload the Xbox.

Dont have a Gamecube so cant prove this.

What you can do quite easily is fit a diode in series with pin 8 in each of
the
SCART plugs which will prevent this from happening.

Its really annoying that they DONT switch Pin8 because any piece of
equipment
powered up will grab the TV even though you may not have that input
selected :-(

Hope that helps

Keith

www.diyha.co.uk
www.kat5.tv

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