Somewhat failed SNES 50/60Hz mod - lockout chip mod

I just spent the evening modding my PAL SNES with two switches for 60Hz switch and lockout chip switch.

I can confirm mod works, I get 60Hz screen (full size) and lockout is disabled because Final Fight 3 and Donkey Kong Country runs without problems (both USA releases).

But I can not turn off 60Hz to go back to 50Hz, in both positions I get 60Hz, the same with lockout chip. Final Fight 3 and Donkey Kong Country runs fine with lockout switch switch in either position.

The lockout mod is the usual pin 4 lifted on the lockout chip, attached with Kynar wire to middle pin of switch, left pin get 5v right pin get ground.

The 50/60Hz mod is the one where pin 30 and pin 24 is lifted and connected to middle pin on switch, 5v on left (throgh resistor) and ground on right.

Just like: http://www.gamesx.com/importmod/snes5060.htm and http://www.gamesx.com/importmod/sneslockout.htm

(I got 5v from "O" and Ground from "G"). Anyone knows the problem?! :crying:

 

7805 regulators will output 5v which is exactly what you're seeing. You did put the 2.2kohm resistor on it did you?

Doh, just read that you did that. Apparently if they both receive 0v or "float" it will default to 60hz. For some reason the chips aren't being fed +5v for some reason. I'd check your connections just to be sure.

 

Yes, I have the resistor, it says on the package I received it in: "2.2 ohm 0.25W", is it the same as a 2.2 kohm resistor?

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edit:

Ops,, I guess I need a 2.2 Kohm resistor and not a 2.2 ohm resistor, just noticed the store got kohm variants also :redface:

Glad I did not brake anything, got my Everdrive in the system :033:

 

I doubt you'd have killed anything, just fed it a different amount of current...

2.2amps versus 0.0022 amps. :thumbsup:

 

Thanks for the help :clap:

Looking forward replacing the resistor :Rock:

 

Still I'm not exactly a professional electrical engineer but I would think that feeding it too much current wouldn't matter and that getting 5v would be enough.

But I also know that people typically don't put resistors into diagrams like that purely for kicks.

 

An update, got my 2.2kohm resistor today and replaced the 2.2ohm resistor I had in it but the SNES behaves the same.

In the Super Everdrive toolbox SNES is recogniced as region NTSC no matter if the 60/50Hz switch is switched to ground or 5v.

Lockout chip is also always disabled no matter how the other switched is turned.

I double checked connections, I have taken ground from "G" and 5v from "O".

The only solution I can come up with is that I have fried the switches when soldering on them and they both got stuck in 5v mode?!

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Update:

Just for clarification, on each switch I have 5v on left pin, ground on right pin and on the middle pin I have the pin 24 + pin 30 for controlling 50/60Hz and on the other switch I have lockout chip on the middle pin.

Update 2:

-Removed 50/60Hz switch and soldered 5v+resistor to pin 24/30, same result.
-Tried pulling 5v from a new solderpoint, same result.
-Tried ground from new solderpoint, same result.
-Tried without soldering ground or 5v to pin 24/30, same result (I thought they had to be grounded to get 60Hz?)

Update 3:

F"n hell, the kynar cable I used for pin 24+30 was aparently broken, I replaced it with a new cable and now 50Hz works again! !!

 

LOL. I love it when that sort of thing happens. Last mod I did I had to pull out a continuity tester to find out where my soldering had gone wrong. Found two whole pins that needed solder.

 

Hehe yep

Time to do the same mods on the MegaDrive now!

 

Nice one. At least it didn't get messy. I've had incidents where I've missed the simple problem and practically destroyed the subject in question to find the answer.