SNES Rockin and Rollin

[anacreon]

OK although the SNES was never officially released in my country (South Africa) I did manage to buy one about a year ago via a local swap-shop. It is an American model (boxy shape, purple switches), but when I got it it output a 50Hz PAL signal.

Now after eventually opening it it looks like someone did a very cunning mod-job on the machine to get it to do PAL. The usual pins were changed on the main chips, but it looks like they also installed a RF box inside the machine that outputs a PAL signal.

Well to make a long story short (too late) I re-modded it back to NTSC, since my TV can do NTSC no problem, and all the decent games are NTSC anyway. The mod seems to have taken because while it still boots up in PAL50 mode it immediately switches to 60Hz and all my NTSC games play fine.

Except that now whenever the screen becomes too bright (like on one of the brighter levels on SMW or in the hallucination scenes in Secret Of Mana) the screen starts to roll.

The machine always did have a problem with bright screens - even when it was still modded, but then all that would happen is some slight distortion at the top of the screen (like a bending of the graphics). Now the whole screen starts rolling - making it impossible to play.

I know there is nothing wrong with my TV, since it can do 60Hz from my cube with no problems, and I have various DVDs and other game consoles outputting NTSC to my TV without a problem.

What I want to know is - did the NTSC SNES ship with an internal RF box? If not then is it safe to remove the box now? Will that solve my problem? Why is the machine still booting into 50Hz mode despite the fact that I've reconnected the pins and start the machine with a NTSC game?

[NFG]

If you're not using the RF box you can safely remove it.

Yes, the US SNES shipped with the RF box originally.  It probably won't solve your problem, since clearly the system isn't 100% returned to normal operation (it shouldn't boot to 50Hz).

Why not buy a US model SNES PCB?  Shipping shouldn't be more than a few pennies.  A JP PCB will also fit inside your case, I believe.

[phreak97]

if you have returned all the ppu pins to the pads benieth them, and undone any other crazy mods people have done, and you are still getting pal50, then i guess it is actually possible someone has put a pal snes motherboard in an american shell. i was actually planning on doing that and selling them modded on ebay here for the australian snes fans. but i never found a source of good condition snes shells.

if there are any model numbers or anything printed on the motherboard, would you mind posting them here?

also are you sure it starts in 50hz then switches to 60hz? i cant see any logical reason for this to happen, or any possible way even, unless you have some extra circuitry added in there for some reason. if that is the case, you could probably rip all that out:/

im no expert on video, but it sounds like bright screens are causing your snes to lose its sync signal.. (complete stab in the dark here: could it be that the sync signal is already weak and when the picture signals get more intensive they somehow overpower the sync signal causing the tv to lose it?) there should be someone around here who knows enough about the way the snes makes its composite video to be able to tell you how to fix that. also, if your tv has scart, using rgb might fix your problem, also, once using rgb, it makes no difference at all whether your snes is pal or ntsc.

[anacreon]

Well I'm pretty sure it is a real NTSC SNES, since the fit looks right. Does the PAL model's mobo fit in the US model's case properly? I am pretty sure it is a US mobo mainly because it was modded to get PAL. I know this because quite a few of my games used to boot up saying "this game is not designed for your system - PAL" PLus the borders and slowdown etc.

Where would I go about aquiring another mainboard for my SNES? Ebay (or rather Paypal) has banned all credit cards from SA.  :angry: I might as well just import a whole new SNES - mine is a bit yellowish.

I looked at the back of the board and there are numerous leads coming from the RF box soldered to various points on the board - I know manufacturers sometimes do this to fix manufacturing faults, or to make slight improvements, but I doubt Nintendo would do it - aren't they generally more careful about stuff like that.

I don't use RF at all. Currently I'm using the composite cable that came with my Cube. I did order that multi-system S-Video cable from Lik-Sang, and as soon as I have a TV that is capable of S-Video I will use that. Would using S-Video fix this rolling problem?

What might be happening is that when it boots it detects that the RF switch is PAL, but then immediately changes once it clicks that I'm using composite.

Tragically - like Australia and NZ, we don't get much stuff with SCART plugs on it here in SA. Most TVs don't even have S-Video, never mind component. My 54cm Samsung Plano is composite only.

[phreak97]

yes, a pal motherboard will fit in an ntsc shell perfectly. and even a real pal snes has the slowdown and boarders.
first, check there are no components removed, and there are no traces cut, then rip off all those wires, nintendo didnt put them there.
i really wish you could get some goodd pics of both sides of the motherboard.