SNES vertical line issue

[Drakon]

http://www.tmeeco.eu/BitShit/OneLineOfNoise.jpg
http://www.tmeeco.eu/BitShit/VerticalBarFix.jpg
http://www.tmeeco.eu/BitShit/IamNotS...arAnywhere.jpg

You and your fancy scope thing.

[akaviolence]

http://www.tmeeco.eu/BitShit/OneLineOfNoise.jpg
http://www.tmeeco.eu/BitShit/VerticalBarFix.jpg
http://www.tmeeco.eu/BitShit/IamNotS...arAnywhere.jpg

I'd like to give this a try. Can you provide more info on what cap sizes you used and where you put them etc?

[Drakon]

I'd like to give this a try. Can you provide more info on what cap sizes you used and where you put them etc?

....100 uf 10v (or 10+ v) for the polarized ones, 0.1 uf for the non polarized, where they go is shown in this picture.

[omp]

http://www.tmeeco.eu/BitShit/OneLineOfNoise.jpg
http://www.tmeeco.eu/BitShit/VerticalBarFix.jpg
http://www.tmeeco.eu/BitShit/IamNotS...arAnywhere.jpg

Wow that's an old 'un, but probably as reliable as something that is very reliable.

[akaviolence]

What about the smd caps soldered to the legs of the 104's? Are they necessary?
Also, wouldn't 6.3V caps suffice? Just to get the physical size down, or do the 10V'ers fit under the board with no clearance issues?

[Drakon]

What about the smd caps soldered to the legs of the 104's? Are they necessary?
Also, wouldn't 6.3V caps suffice? Just to get the physical size down, or do the 10V'ers fit under the board with no clearance issues?

Oh wow I didn't even notice it looks like smd caps are added on top of existing caps haha. 6.3v should be fine everything is 5v in a snes.

[akaviolence]

That's why I was originally asking TmEE, so that he would answer with specifics instead of telling me what I can already extrapolate from the picture.

[madmax2069]

My system don't get this exact issue (i have seen many of my friends systems that have, I just chalked it up to a old TV, or bad video connection), but I do get some nasty looking scrolling green lines. I don't know the what the issue is. I can rule out the TV because it happens on any set I try it on, I cant however rule out a faulty power supply (due to its my only one), and can't rule out possible hardware failure of the system itself (failing chip, or failing caps) due to it being my only SNES system, and no real testing gear).

Its my first SNES I have seen with these scrolling green lines. When I first power the system on, these green lines do not show up, it takes about 30 minutes of play time for them to show up. They also only show up when graphics are being displayed, they go away when only showing a blank screen and reappear when any graphics are shown.

Being that I found this system, it could very well why the system was left behind. Or it could very well be from sitting in a attic for so long.

[shymog]

http://www.tmeeco.eu/BitShit/OneLineOfNoise.jpg
http://www.tmeeco.eu/BitShit/VerticalBarFix.jpg
http://www.tmeeco.eu/BitShit/IamNotS...arAnywhere.jpg

The SNES2/SNESJr also has the problem (though reduced). Is there a way we can get a bit more info about which lines we're working so we can apply this awesome find to the later unit? I unfortunately don't have the luxury of having a sample of both units on-hand for comparison so if it comes down to it I can do that, but I figured I'd ask.

[TmEE]

I just slapped on a bunch of ceramic caps I soldered from a dead PC mobo, I do not know their values but they range from 0.01 to 0.1µF for sure, judging by size on the high side.
The ceramics have a lot better effect than e-caps. It is high freq noise there and the ceramics are there just for that.

[mvsfan]

my genesis wouldnt capture on my pexhdcap until i boosted the sync, But it played on my tv fine, go figure.

[Drakon]

my genesis wouldnt capture on my pexhdcap until i boosted the sync, But it played on my tv fine, go figure.

Some hardware is better than others.

[xrgb]

I just slapped on a bunch of ceramic caps I soldered from a dead PC mobo, I do not know their values but they range from 0.01 to 0.1µF for sure, judging by size on the high side.
The ceramics have a lot better effect than e-caps. It is high freq noise there and the ceramics are there just for that.

Thanks for sharing this.

1. Which SNES PCB revision was this done to?
2. What devices did you add the extra decoupling caps? WRAM? PPU2? Voltage Regulator? Anywhere else?
3. Adding 100µF and 0.1µf two the two points shown should be effective enough? You make it sound like the electrolytics aren't really needed? Or just that the ceramics take care of the noise, while the electrolytics handle current?

I saw the comment above about trying switching regulators instead of linear/"buck" regulators. However, I'd imagine something like this could offer an improvement (lower dropout and 1% tolerance):
http://www.digikey.com/product-detai...C5T-ND/2337056

[Miyamotos RGB NES]

Basically all we now know is that capacitors need to be soldered in at thus far undetermined places on the bottom of the motherboard?

I looked at the bottom of my 1CHIP SNES and there's no spots that look anything like where TmEE showed in his photo. Is there any way to figure out where these caps have to go but on a 1CHIP SNES? TmEE, can you simply tell us how you knew to solder them in those spots so I know what to look for on the newer motherboard revisions?

Also, in this photo:

http://www.tmeeco.eu/BitShit/VerticalBarFix.jpg

I just noticed a bunch of resistors soldered up top (near R19 and such). What are those for???

[TmEE]

Those are all ceramic capacitors not resistors.

You have to solder at least one ceramic capacitor per power pin on a chip and at least one e-cap per chip. Nintendo omitted the e-cap part and only has one ceramic per chip instead of per pin.
I only have access to that particular mobo on the photos I have made. I don't have other SNES versions. But theory is same regardless of mobo version.