Mega Drive 2 50/60Hz and JPN/Eng Switches
UPDATE May 2011
I've left the old guide in place in case you
want to check something out on it. Hopefully the new guide is a lot
clearer to follow. Please note, I've done this on a VA1 motherboard,
haven't seen any others to try it on but the principle should be the same?
(perhaps need to check Lin83s info linked below)
Here's how I've wired the switches. Red for 5 volt, Black for GND - you can see the black and red wires go from one switch to the the other, this saves having to solder lots to the motherboard. When it comes to fitting the switches, have a look here.
First up, PAL/NTSC - 50/60hz (whatever
you want to call it) switch.
You will need to either use an RGB cable to
get a colour image at 60hz after performing this mod, or
perform a
colour fix mod which I haven't tried yet.
You can see from the photos above that I've cut a trace that leads to leg 46 of the nearby chip. This leg is used to select the video mode - 5v for 60hz or GND for 50hz. I've labelled the points I've used for 5v and GND which are nearby where you're working. You can also see I've scraped the green coating from the trace leading up to leg 46, then added some solder to it.
And here's the switch wires attached to their relevant points. As always, I've stripped, twisted and tinned these wires. For the white wire, I just held it in place on top of the scraped trace below, and heated it up with my soldering iron, the solder on the trace and the solder on the wire then melt together. Try to resist giving it a tug too hard to see if it's stuck properly! That was relatively easy right?
Now to the language switch
This time we're working with leg 107 of the
same chip. This time, GND is for Japanese and 5v is for English.
My previous guide had you lifting the leg of the chip, that's quite fiddly really and I try to avoid it if I can now. So instead, cut the trace that leads up to the leg, and inbetween the cut and the leg, scrape some of the green coating away, again - add some solder to this cut exposed trace.
That's it, that's the soldering done. I soldered the blue wire from the second switch in place using the same technique as above. The switch gets power from the other switch, so in total you've just got 4 wires going to/from the motherboard - GND, Power, Video Mode and Language.
You can mount the switches where ever you want, I usually go for the side of the console opposite the expansion bay.
NOTES
(I also need to read and digest the info from Link83 below)
Link83 has sent some useful info :-)
I strongly recommend that you dont suggest lifting the legs on the Sega ASIC's,
since I have read of at least one person snapping the legs off doing this, which
kills the Mega Drive. I think it would be much better to list the Mega Drive 2
motherboard revisions:-
http://www.sega-16.com/forum/showthread.php?7796
From there you can see that there are the following MD2 motherboard revisions:-
VA0, VA1, VA1.8, VA2, VA2.3, VA3, VA4
However, most of those revisions use pin-compatible Sega ASIC's, so you can
narrow down the list to just three types of ASIC:-
VA0, VA1, VA1.8, VA3
VA2, VA2.3
VA4
See this thread for more details:-
http://www.sega-16.com/forum/showthread.php?16610
Since there are too many MD2 motherbaord revisions to write a guide for every
one, you could just list which two pins on the three ASIC types control the
50Hz/60Hz and JPN/ENG settings, and then recommend that people follow the traces
until they find a set of jumpers on the motherboard. Then if there are no
jumpers present suggest cutting the trace leading to the pin and soldering to
the very tip of the pin (Being careful to not bridge pins on the ASIC) and
finally as a last resort lift the pin and solder to the leg itself.
A big credit must go to Klaus at Woflsoft, this guide uses the chip pinouts that I read on his brilliant site.
Summary of Components needed
2 x Single Pole, Double Throw
switches
thin wire
(I purposely didn't use Kynar, just to show that you don't always need it,
I think this was pulled from an old network/ethernet cable)
