SNES Vertial Lines Issue

[nightrnr]

I too, recommend finding an older tube TV to see if the signal is just getting confused on some newer TVs.

Also, I have a similar issue on one of my SNES systems (vertical lines and wrong colors on sprites).
See link:
viewtopic.php?f=17&t=46426

It's minor compared to this, but I still think it makes it unplayable. I can't handle playing on real hardware and not seeing sprites correctly.

Also, I DID replace all the caps. It didn't help at all. So mine probably is a PPU issue, which is beyond my skill to remedy. It's too bad too, as between the 2 systems, we probably could have a working one.

[Ziggy]

Just to chime in, I have a similar problem with my original SNES. I never made a thread about it though. I don't have vertical lines. I have some garbage graphics on screen, seems random what it is. Usually the sprites, and the jump when you move a sprite. After making sure the cart slot was 100% clean, I figured it was the PPU. I didn't bother with a recap, but it might be worth a shot.

edit: There's a RAM chip (you can see it in one of the pics posted by jamescurtis24) labeled S-WRAM. I'm not sure what this RAM is used for, but if it's for video, than it's possible that the RAM went bad (and not the PPU) and that's what's causing the issues.

[nightrnr]

edit: There's a RAM chip (you can see it in one of the pics posted by jamescurtis24) labeled S-WRAM. I'm not sure what this RAM is used for, but if it's for video, than it's possible that the RAM went bad (and not the PPU) and that's what's causing the issues.

According to a couple things I read (the accuracy of which I have limited knowledge of, but seems to make sense):

WRAM - writable random access memory
from:
http://snesemu.black-ship.net/misc/hard ... labels.txt

The snes S-WRAM chip seems to be entirely proprietary dynamic ram. It allows the CPU bus and a separate bus for the PPU and other peripherals to share it. I've never seen this kind of thing from an off the shelf component.
from:
http://www.assemblergames.com/forums/sh ... -wram-help

and back to that 1st link

PPU - picture processing unit

He assumes the PPU1 chip is the one used for video and the PPU2 chip for mode 7.

If all that is true and the PPU1 is failing on a lot of SNES consoles, I wonder if there are any ways to save them.
If it's so often the same chip, I wonder why everyone experiences different graphical anomalies? Vertical lines seems to be a common ground, but usually on different layers and/or sprites.

[Ziggy]

If all that is true and the PPU1 is failing on a lot of SNES consoles, I wonder if there are any ways to save them.
If it's so often the same chip, I wonder why everyone experiences different graphical anomalies? Vertical lines seems to be a common ground, but usually on different layers and/or sprites.

Which is why I was thinking RAM. Different areas of different RAM chips are going bad, causing slightly different problems on each console. Same could apply for the PPU, I suppose, different areas of the IC are going bad.


If it's a proprietary chip and it's going bad, there's nothing that can be done. There's no replacements. Unless you swap one from a known good working console, but then there's no point. Might as well just use that working console instead. Unless you have a console that's broken in some other way, put two broken consoles together to make one working console.

And on that note, I'd like to make a public service announcement (this isn't at any one in particular, this is just one of those thoughts that really bothers me). Don't ever throw away "broken" consoles or game carts. They can either be repaired or used for parts to fix another broken console. Never throw anything away. Even if you already parted out something broken, still save the rest for some one else that might need it. If you don't want it and just want to get rid of it, give it away before throwing it away.

He assumes the PPU1 chip is the one used for video and the PPU2 chip for mode 7.

I am FAR from an expert here, but from everything I've read, that's wrong. I've read multiple times from multiple sources that the PPU1/2 design can really be thought of as one chip because of how closely the two work together. The PPU2 chip has to do a little more than just mode 7.

[nightrnr]

Which is why I was thinking RAM. Different areas of different RAM chips are going bad, causing slightly different problems on each console. Same could apply for the PPU, I suppose, different areas of the IC are going bad.

I follow you.
That's why it would be so important to know what chip is causing the specific issue though. Only then could you weigh your options.
I'd love to get to the bottom of this (it's becoming far to common to ignore).

And on that note, I'd like to make a public service announcement (this isn't at any one in particular, this is just one of those thoughts that really bothers me). Don't ever throw away "broken" consoles or game carts. They can either be repaired or used for parts to fix another broken console. Never throw anything away. Even if you already parted out something broken, still save the rest for some one else that might need it. If you don't want it and just want to get rid of it, give it away before throwing it away.

Agreed
Some other guys echoed your sentiments on the SNES thread that I started:
viewtopic.php?f=17&t=46426

We should add a "System/Cart Junkyard" to our buy/sell thread. I hate resorting to ebay when I need a part and the price is jacked up so far that I may as well buy a whole broken unit.

He assumes the PPU1 chip is the one used for video and the PPU2 chip for mode 7.

I am FAR from an expert here, but from everything I've read, that's wrong. I've read multiple times from multiple sources that the PPU1/2 design can really be thought of as one chip because of how closely the two work together. The PPU2 chip has to do a little more than just mode 7.

It probably depends on the game too. One cart might actually use the PPU2 more exclusively for mode 7 while another uses it to display separate layers or something.
It's all speculation for me though, so I'll stop posting ideas that could be false.