I want to add a 60hz switch to a PAL Sega Saturn I've picked up. I found this guide online, which looks nice and easy: http://www.retrocorner.net/index.php?Mods_/_repairs:Saturn_model_2_50/60hz_switch_-_page_2 As you can see it requires just 2 wires to be soldered near the battery. However I just opened up my Saturn and it has a different motherboard, this kind: Which as you can see, does not have the "SW4" area of jumpers as per the guide. So does anybody know the easiest way of adding a 60hz switch to the version I have? I know there are much better ways of doing it such as the switchless region mod, but I have neither the equipment to flash the chip required or soldering skills to do it that way. So I just want the easiest possible way of adding a 60hz switch. Please let me know if you can help.
the only other way i think is to left a pin on the chip and hook it up to a switch that either connects it to ground or +5v, that's how i done mine, that and a region free bios. but some soldering skills are really required.
I can do basic soldering, but I really wouldn't be comfortable trying to solder to something as small as a chip leg. So there's no other way on later models?
Both locations are at the back, the one with JP1/2 is under the video encoder, the other is in the middle of the board (look for TP22). Solder a cable to the yellow point, this is your signal to the VDP2 which controls 50/60hz. Set up a on/on switch with this cable at the middle, 5v on one end (60hz), GND on the other (50hz). Personally, I route the signal cable back up next to the communications port, then get the +5v and GND signals from the unpopulated CE102 capacitor slot (above the SEGA logo), join all 3 cables in shrink wrap tubing from that point on, and put the switch in the little plastic that goes around the batters to stabilize the mpeg cart. The switches I use, they are just a bit wider than the huge empty part in that little plastic try, so I can push the switch in there in a way so it won't budge at all. No need to mess around with hot glue, and the mpeg cart still fits above it. If the machine does not boot afterwards, you'll also have to carefully raise pin 1 of the 315-5746 and connect it to ground (this can only happen in VA7 PAL and VA9 boards; VA13 PAL boards use a different, independent chip there).
Thanks for the advice. I've already bought a single pole/single throw switch (which only has 2 connectors on the bottom) as that's all that was needed for the 'SW4' method. So do I need a new switch too?
Technically an on/off switch may also work as the VDP2 pulls the pin low if it is left floating, but it is best to use a on/on switch, just in case. Some components don't like being left afloat.
Leaving input pins floating on CMOS chips is a little too evil for my tastes - sure, you can get away with it most of the time, but I'm old enough to have seen chips destroyed thorough latchup when pins were left open.
If fact, that's my preferred approach, too - having wires with a low impedance connection to VCC running aound the unit always seemed like asking for trouble. The ones I've modded recently don't use a switch at all - just a PIC wired into the reset circuit. I also prefer to lift pins than cut traces, just in case you ever find yourself wanting to revert the mod.