Single Switch Region Mod

[MEGADRIVE Jeroi]

if i cut this one http://www.segakore.fr/images/articl...tch_md2_07.gif the MD is only USA one (genesis)

i don't have jumper in my MD i need to isolate the 107 pin and provide it 0V

so my circuit should work no?

By default your 107 is getting 5+, your JP3 should be connected with trace to +5. With US console, you need to cut that trace and also JP3 trace I guess. Because theres got to be some difference in genesis 2 model than pal mega drive 2 model. Also lift the 107.

When done these actions for ON-OFF-ON switch mod, Your genny should still run as US console if this is doable. Other wayyou need to have ON-ON-ON switch and solder all the way mmmonkey explains.

[dadou]

i don't understand something i don't have the jp3 i have a pal megadrive not the genesis one

you're right i have by default 5v on the pin 107 ANG and the pin 46 by default 0v 50hz (Pal)

so i need to replace the switch by ON-ON-ON one instead the ON-OFF-ON one and if should work right?

[Devil N]

Technically, the single-switch region mod should work on an MD2, but I've never tried my hand at MD2 modding, so I can't confirm it. The switch mod guide as I wrote it only applies to the MD1, specifically the PAL VA4. The MD2 doesn't have those convenient jumpers that the MD1 has, which complicates things, especially with the pin lifting and all.

Anyway, if one of the pins on MD2 defaults to 0V, then yeah, that changes things. I think it would probably be easiest to implement this with a double-pole on-off-on switch, though there might be other ways. Let me just sketch up a diagram.

[edit]
This is what I came up with:



In the middle (off) position, pin 46 defaults to 0V (PAL) and pin 107 defaults to +5V (Eng), making the console European.
In the right (on) position, pin 46 is connected to +5V (NTSC) while pin 107 defaults to +5V (Eng), making the console American.
In the left (on) position, pin 46 is connected to +5V (NTSC) and pin 107 is connected to 0V (Jap), making the console Japanese.

Again, this is just theoretical and based only on the information you've provided, so you'll have to check for yourself if this is correct.

P.S. Jeroi and TmEE: thanks for the endorsement.

[MEGADRIVE Jeroi]

i don't understand something i don't have the jp3 i have a pal megadrive not the genesis one

you're right i have by default 5v on the pin 107 ANG and the pin 46 by default 0v 50hz (Pal)

so i need to replace the switch by ON-ON-ON one instead the ON-OFF-ON one and if should work right?

IF pin 46 is connected to GND then you might try to brake the trace to leave pin 46 without gnd connection. Then try to turn on your megadrive, and see if it is in 60hz mode. If yes, then md2 has the same factory fault, where 46 pin provides +5 by default without trace. If md2 dont work at all, then you need to give gnd or +5 to pin and this makes the mod undoable as single pole ON-OFF-ON.

The theory of md1 single switch mod assumes, that when jumper pins are not connected to any +5 or gnd pin, system chip defaults someway pins to +5 thinking that the console is US version. Only way to discover this is to turn md on, and see if game starts to load and see if it is in what mode. This gave Devil N the superior theory to make On-Off-On switch mod just by providing GND to jumper pins.

So, when 107 leg is lifted, jp3 46pin is cut without a trace to any gnd or +5 source, md2 should think itself now US version. Then in theory you could provide gnd to 107 or 46 to make the console some other mode than US. Only way to discover this is to mod a md2 test run with game while modding. Your console will not brake if your jumpers are not connected proberly, as only you can give either +5 or gnd theres no +7 or +10 or +12 or lighting strike to breake your console. And please report if you can figure it out.

[dadou]

IF pin 46 is connected to GND then you might try to brake the trace to leave pin 46 without gnd connection. Then try to turn on your megadrive, and see if it is in 60hz mode. If yes, then md2 has the same factory fault, where 46 pin provides +5 by default without trace. If md2 dont work at all, then you need to give gnd or +5 to pin and this makes the mod undoable as single pole ON-OFF-ON.

my MDII VA1 have the same factory fault i test it

so the diagram of Devil N should work

PS: Thx Devil N

[MEGADRIVE Jeroi]

my MDII VA1 have the same factory fault i test it

so the diagram of Devil N should work

PS: Thx Devil N

Please report how did you do the single switch mod to md2 and I shall write new diagram for md2 also for this trhead and we shall be the first in the world to give people single switch mod for md2.

[dadou]

i didn't do it right now because i don't have a 3 position switch with 6 pins (only have one with 3 pins) so i can't test the diagram of Devil N perhaps this weekend if i can find a switch

[MEGADRIVE Jeroi]

i didn't do it right now because i don't have a 3 position switch with 6 pins (only have one with 3 pins) so i can't test the diagram of Devil N perhaps this weekend if i can find a switch

Well try with the 3 pin switch first. provide gnd middle and pine 46 right and 107 left. See what happens when you have done that... If you got that gnd off from 46 and lifted 107 and it is us version mode, then the normal ON-OFF-ON diagram may work with you. You need to just provide than gnd for 46 to make 50hz, gnd for 107pin to make it jp.

[dadou]

so i need to do like this:

left = pin 107
middle = GND
right = pin 46

Do i need to cut the trace of the pin 46 and 107 or not?

[MEGADRIVE Jeroi]

so i need to do like this:

left = pin 107
middle = GND
right = pin 46

Do i need to cut the trace of the pin 46 and 107 or not?

First things first:

1. cut the gnd (0V) trace from 46pin
2. lift the 107 pin from chip to lose
3. fire up md2 see if it is in 60hz mode english

If yes:

Then
1. solder red to pin 107
2. solder green to pin 46
3. solder black or green/yellow to gnd spot on mobo
4. solder green to left pin of switch
5. solder black to middle pin of switch
6. solder red to right pin of switch
7. fire up md2 and try your switch and see if it works
8. If not, try cut the jp3-4 jumper trace which is +5 volts I guess
9. fire up again the md2 and try your switch

Edit:
I actually studied more the mmmonkey guide for md2 region and 60hz, it seems that this will work, as 107 gets by default +5, lifting the pin will lose the jumper, but it should act like the md1 does, chip providing +5 for the 107 even so. So providing gnd to 107, should change the processors mind and go japan mode. And, when you gut the gnd trace from jp3 or 46 pin, then jp3 is not connected to any +5 or gnd, and if it works like md1 then it provides +5 because gnd was cut of from it. All this makes me belive that single switch On-Off-On is doable.

If no:

Then you need to have atleast 2 pole ON-OFF-ON or 2 pole ON-ON-ON switch.

Remember:

1. While you are in the md2 modding, you are now entering to unknown area of md2 modding
2. You cant breake the md2 by touching only jumper pins, it wont get short circuit what so ever, that is if you dont do anything more harm to mobo than the jumper realted explained in several md2 modding threads.
3. Please report if you can get this work, we will be the first ones to publish then the single switch mod for md2

[dadou]

First things first:

1. cut the gnd (0V) trace from 46pin
2. lift the 107 pin from chip to lose
3. fire up md2 see if it is in 60hz mode english

can i just isolate the 107 instead lift (because i don't love to lift pin i'm afraid to break it)

don't worry about the modding it's not my first mod in my MD II i did some other one

i can do this work i will report you if they work or not

[MEGADRIVE Jeroi]

can i just isolate the 107 instead lift (because i don't love to lift pin i'm afraid to break it)

don't worry about the modding it's not my first mod in my MD II i did some other one

i can do this work i will report you if they work or not

You can just heat the leg and then pop it off, you dont need knife for it. Just solder tip to heat the leg and with screwdriver or other sharp tool give it a little push while tin is melted. One guy reported that while heated the tin, the leg will pop off, on it's own, but this is not reported in any other forums threads so there is only one guy to report this.

You can cut also the trace to that pin next to it's trace, but fixing broken trace is harder than solder the leg back to mobo.

[dadou]

ok let's go for the good news:


It's working!!!!!

here's the diagram:



btw i isolate the 107 pin and the 46 one and it's working perfectly

so now we have a single switch mod for our MDII

[io.]

I did kinda the same with a rotary switch some time ago. http://jomay.free.fr/Consoles/SEGA_M...US-JAP%281%29/
Should be nice to do a switchless mod via the reset button like with the Saturn.

[Devil N]

ok let's go for the good news:


It's working!!!!!

here's the diagram:



btw i isolate the 107 pin and the 46 one and it's working perfectly

so now we have a single switch mod for our MDII

Ah, so pin 46 defaults to +5V after all. Cool, that makes things a lot simpler.