As you found out you can do the single switch to model 2's (& all their revisions). The centre pin is used for ground because that is your common point. If you want further info, go over to sega-16 forums. There is a thread in tech aid dedicated to the single switch mod including colour fix for md2 (not that it matters if using rgb). I helped a dude from New Zealand with his and it wasn't that difficult. It shows rev0, 1.0 & 1.8 if I remember correctly. If you have a genesis 2 rev 2.3, 2.4 or 3 sega were nice enough to revert back to naming all of the jp points, instead of just the 50/60hz point.
Yeah just done it this evening, i used a combination of MMONKEY'S 2 guides for the 50/60hz mod, i used the ground point from his new mod guide and the left hand side pad of JP3 from his old guide (not sure why he change to a new way of doing it as the new way is more difficult than the old). And then used his new mod guide for the 'lang mod' and instead of lifting pin107 leg on the chip i stripped away the trace coming from pin 107. A real easy mode with just 3 solder points on the board. Is it right the switch should be wired up so the selection sequence is PAL/US/JPN??
That is correct as middle switch position, neither JP points are grounded so pins (on IC) are high which gives 60Hz and English language = USA.
Cheers, im thinking of giving a 4 point switch mod a go, im guessing you wouldnt need to solder any more points onto the main board, but add a daisy chain wire on the switch side. ill have to look at a schematic of a 4 point switch to see how it works Hmmm, all im able to find for a dp4t switch is a on/on/on/on configurations, id need a on/off/off/on or on/off/on/on config wouldnt it?
You really need to source the data sheet for that switch. Depends on the design of the switch. I use 2 types of 3 position switches- 1/Smaller type (but is actually 4 pole!) has 4 pins (on each pole) 1 being common the other 3 being the positions. 2/larger type (2 pole) has 4 pins (on each pole) but the pins are paired. As the switch goes along (position 1) pins 1 & 2 are switched, (position 2) pins 2 & 3 are joined, (position 3) pins 3 & 4 are joined. So for the switches I use 1/ is wired as GND goes to common (we'll call this pin 1), pin 2 goes to JP2 (to get PAL), pin 3 is not connected (For USA), pin 4 goes to JP3 (For JPN) 2/ is wired as GND goes to pins 2 & 3, pin 1 goes to JP2 (position 1= PAL), position 2 is bridged to ground so no JP points are connected, so this makes USA, pin 4 goes to JP3 (position 3= JPN). So yea if you get the data sheet should be able to work it out easy enough, especially being double pole.
Well thats the switch, http://www.ebay.co.uk/itm/10-Pcs-ON...al_Components_Supplies_ET&hash=item43b313dcc5 not sure if the info provided is of any use!?
That looks to have a common point. See how the pins go- I I__ I I I <POLE 1 1 2__3 4 5 I I__ I I I <POLE 2 6 7__8 9 10 IF (you will have to confirm with a multi-meter) it is similar to mine 1=JP2 (PAL) position 1 2=ground (common) 3=not connected (USA) position 2 4=JP3 (JPN) position 3 5=JP3 (Asia) position 4 6=not connected (PAL) position 1 7=ground (common) 8=not connected (USA) position 2 9=not connected (JPN) position 3 10=JP2 (Asia) position 4 Again you will need to confirm with a multi-meter, but it will be along those lines......
Correct We are grounding both JP points, so from the diagram previous that shows (as you say) 50Hz and JPN language.
Cool, well ive order the switches, so will probably take a week or so to get here as coming from hong kong
One thing i did notice on the PCB are these solder pads... noticer the few pads tht have the green coating worn away, would this cause any issues?? Is this megadrive basically buggered then or can it be fixed??
Switches turned up today, can you help me out on how to test this switch, its making my head hurt thinking about it
