moddin japanese mega drive 50/60 jap/eng

I have this model 1 jap va6 md which I wanna mod but the jumpers positions are different from the pal models i usually mod. this model was also premodded for the asian pal market (pal60 composite colour mod, blob of solder between jp2 and jp3 under the pcb which I just desoldered to have native 60 hz back and trace near jp4 cutted always under the pcb)

jumpers are positioned in this way

o-o jp4
o-o jp3
o-o jp2
o-o jp1

anyone can help me give me the right tips for having switches from these jumpers?

many thanks

 

The jumpers are the same as what you'd find in a Genesis or PAL Mega Drive; for example JP1 is JP1 no matter what system you're working on.

 

thanks for always helpin me apolloboy
i knew this fact but I m a little confused about which row of solder points gives the +5v and gnd, the left one or the right one?
and for jp4 trace cutted, I have to solder a wire under the pcb?

 

If you look at the underside of the PCB at the jumpers, you'll notice that two pads, one from each jumper, are connected together. The pads on the other side will not be connected together and those will be your 5V and ground pads. Alternatively you can also use a multimeter to figure out which pads are connected to 5V or ground.

If it's already been cut, don't add a wire. You're using a switch after all so you want that jumper to remain severed.

 

many thanks apollo, and cut always between jp2 and jp3 traces, right?

 

If you're wiring up both language and 50/60 Hz switches, all the jumpers need to be disconnected.

 

thanks again