Jap mega drive model 1 question...

[faxanadu13579]

Hello i have a jap mega drive model 1 which was already coverted to run at 50Hz when i bought it. The problem is that I want to change it and make it run at 60Hz but i'm not certain what to do...I opened the machine and here is what i saw:

The outer sides of JP2 and JP3 have been soldered and are connected. Besides that

the outer and inner sides of each JP is connected to each other with a trace. That's all!

Thanks