Master System 2 adding A/V Out
One of the things missing from the cut-down Sega Master System 2 is the A/V out port. Making it impossible to get an RGB output from the console without some modification.
This guide is based entirely on the information on Mike Gordon's site, his guide covered hard-wiring a Scart lead to the motherboard, this guide is slightly different - it adds an A/V port, allowing you to use a Master System 1/Megadrive 1 Scart lead. A copy of the Mike's guide can be found here, just in case his site vanishes.
Adding one isn't too difficult, you'll need to remove the motherboard so that it's possible to solder onto the underside of it, and cut some holes in the casing to mount the A/V port. Here is the 8 pin din socket, mmmonkey has already "tinned" the contacts on the rear of the socket. Also, here is an example of the hole cut into the rear of the Master System 2, used to mount the socket.
As well as the 8 pin din socket, we'll also need some Strip Board/Vero Board (cut so it's 16 tracks wide, and 10 holes tall), 4 220uF 10v Capacitors, 1 10uF 10v capacitor and some suitable wire. Capacitors are polarised, they have a positive and a negative leg, the negative leg is usually marked, in the following picture you can see one capacitor showing black arrows with a "0" written in them, this is showing you the negative leg. If you've looked at Mike's page for a similar mod, you'll notice the resistors used, they are not necessary for this mod, as the resistors are included in Master System 1/Megadrive 1 Scart leads.
Constructing this on Vero Board makes the mod very easy, and here's a diagram showing the layout mmmonkey used for the Vero Board, it could have been made much smaller, but mmmonkey kept it this size as it fits in the console very well, and you don't have to cut any tracks on the board.
Look for a chip on the motherboard labelled "Sony CXA1145", in this picture it is located near the RF Output. This chip is what we'll need to solder most of our wires to, but to make the job easier, we'll do it on the underside of the motherboard - also pictured (please note the black wire was already there!).
The first wires we'll solder are for the RGB signal, Red needs to be soldered to pin 23, Green to pin 22 and Blue to pin 21. There are already some convenient solder points linked to these pins on the underside of the motherboard. Cut the wires so they are about 20cm, make sure you "tin" the wire (melt some solder onto the bare stripped wire), you may also want to add some more solder to the points.
Next solder a wire to pin 12, this is used for the RGB switching voltage. mmmonkey has used white wire, route the wire around as shown, then cut so it is the same length as the RGB wires.
Now we'll solder a wire to pin 20, this is for the composite video signal, solder the wire as shown, again - cut to the same length as the RGB wires.
