Hello everyone, I have a super famicom that I want to bring back in life. I have some image problems it appear when megaman x textbox should come up in the game play. the text appear good in intro. only what is strange is that in the intro the X slide doesn't appear and looks like a electric strike and change to a x on the end. So I saw movie on YouTube with lemmings that I bought to find out if I got the same problems. this movie I have the lemmings working perfectly without any problems so that is to bad. So I place the game super Mario world in and see that the introduction the background layers is black but front layer is correct. You can play and enter the levels only when you change Mario on the map new map of rendering it is getting black the layer.The top layer surrounding with text Mario picture and name of the level still works and I can enter the levels. With street Fighter 2 I got the game also working but the menu selection the button cursor appear but not the text next to it. So I try again a different game Mario Kart what I also enjoy to play. The game starts good when the title menu to select players. This layers doesn't appear. I can selected without seeing it it will go to the player selection so I can select Mario or a other. When I select the cup it still works correctly. When the game starts the background is glitching really hard. I can race but I can't see where I am going. This make me wondering that er was a problem with the VRAM because I check if the address line where still in connection and is for sure. So I change VRAM of place U4 to U5 and U5 to U4 to check if something change with also the other games what I early told. No the same results. So I think the PPU2 is out of order. I hope somebody here had the same? or know where to look ??
Because the revision a CPU is crap. Most broken snes units I see have bad CPU chips, I just threw out a box full of boards that had bad CPU chips. Vram is also a possibility but that usually affects all games, CPU failures are like cancer, many ways they can go bad thus many problems they can cause.
Is it possible that PPU1, PPU2, and VRAM failures don't affect game logic, just the display of the game? Because it is a display problem. I was maybe wondering if it was possible it had the do with DSP1 part I don't know yet which pin connection it use of the socket to the snes main board? Because there is still games that works normal I think PPU1 is good. Than VRAM that had any problem when I swap the place. So PPU2 was first in mind or the DMA connection to import the mode 7 layers part. Still figuring out what the answer is?
You're going to have to make sure the cart connector is clean and all your carts are clean. If no luck, then check all the traces to the cart connector. It's going to take a long time to check all the points, but schematics for that revision motherboard will help a lot.
It could me any of them, it is just CPU failures are statistically more likely, my troubleshooting would be to remove the cpu and put it in another board and see if it works. That is something that just isn't feasible for everyone to do.
Connection I checked. I want to know if I can check it. I had already burn in test cart. He passed all tests. But it only test the Mode 0. I think it happen with the other Mode x numbers. does it to do with the DSP1 ? because I know that mariokart has it. What are the pin connection that this use ? maybe I can track it what is going on there ? I thought Burn in test will find it. To bad not.
Here's a link to the DSP pins. https://www.caitsith2.com/snes/flashcart/cart-chip-pinouts.html#dsp You need to find the schematic for your mobo rev and see where those pins go. use a multimeter to check for continuity. I'll be honest though, it doesnt seem like its just dsp with issues, considering you have problems with super mario world and street fighter 2. If you could take some pictures of the consoles mobo (good clean pictures would help alot) and some pictures on the the pins on the actual carts, that might help too.
Here's someone's repair log where he fixed a ton of Nintendo Super Systems (pretty much a SNES PCB in JAMMA form factor). If you scroll down to the middle of the page it has screenshots of various failures along with which components needed replacement. http://projectvb.com/nss/logs.htm Quote from him on replacement frequency: I came across 24 bad CPUs, 4 bad PPU1s, 4 bad PPU2s, 1 bad APU, and no bad WRAMs or VRAMs. Every failure was in the SNES circuitry, with the exception of the audio/video output (burnt resistors, etc).
