Author Topic: Super Nintendo - Unique problem  (Read 10897 times)

0 Members and 1 Guest are viewing this topic.

Offline Kappes Buur

  • Regular Contributor
  • *
  • Posts: 136
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #25 on: January 25, 2016, 03:38:29 pm »
I would add this diode

 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #26 on: January 25, 2016, 05:04:34 pm »
I have tested the SNES with just 5V on the output of the regulator and it did not damage the regulator.  I got around 2V to 3V on the input of the regulator and distorted sound out of the SNES (the audio op-amps are run from the 10V input that is regulated down to 9V by the transistor).  I believe that the regulator has a built-in protection diode.  I don't think that there are many SNES's that have had the regulator fail due to a reverse voltage input.
 

Offline Mephitus

  • Regular Contributor
  • *
  • Posts: 174
  • Country: us
  • Dashing, no?
Re: Super Nintendo - Unique problem
« Reply #27 on: January 26, 2016, 02:09:46 am »
Actually, it could be even simpler. What is the game? Several have alternate processors on them that could be causing a problem. Especially if other games work properly. Also, Raellz, what state do you live in? If you are in utah, you are welcome to use my scope.

I have Super Mario World 2: Yoshi's Island which does not play at all and I have Super Ghosts n Ghouls. SGnG works at the first logo screen, but updates very slowly. Sound plays without issue. Once it's beyond that first title screen the video goes crazy. Random textures, but the movement of the textures is correct, just not the textures themselves.

I'm in Kansas, but I appreciate the offer!

Sorry for the lack of updates. I've replaced the crystal and all the caps then double checked that the caps are good, still nothing.
Yoshi's island uses the FX2 chipset and GnG does not. So you may want to take that into account for your troubleshooting as games that use the FX and FX2 chipset access the system resources differently. Admittedly, I have never had to repair a system that far gone.
A true gentleman must be prepared for anything. - Pepe le' Pew
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #28 on: January 27, 2016, 12:34:37 am »
Those are way better readings.  To test fast access you need a cartridge that uses fast access rom chips.  The speed of that clock signal is programmed by the code in the game so only some games used the faster speed.  At this point I think you will need to make a test cartridge with a simple program on it to verify the basics of the SNES are working correctly.  Find a cheap game that you can take the non re- programmable rom chip out of and place a re-programmable chip in a socket to run various test programs.  Try and find a Lo-rom based game not a Hi-rom game as this will make loading code a lot easy'er for you.  I made that mistake and was restricted to 32Kb programs not fun.  You will have to rewire the cart to use a standard eeprom chip as the orignal rom chip pinout is nonstandard.  You will also need an eeprom programmer as well.  Good luck on fixing the SNES.  The most likely reason Super Mario World 2: Yoshi's Island does not work at all is because it uses what is called the super fx chip which uses all of the cartridges pins and directly ties into the SNES's graphics chip.  If any of the connections are bad ore the graphics chip is not working correctly the game will not play.  Super Ghosts n Ghouls does not use this super fx chip so it has a higher chance of running correctly even on a broken SNES.  If you could make a video of the corruption you are seeing that would be nice.

Thanks.

I'm going to have to do a lot of research on making my own test cartridge. I've been told I should do it before. The most experience I have on this subject would be programming an Atmega328 for an Arduino and that's kid stuff.

I will make a video for it soon and post a link.
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #29 on: January 27, 2016, 03:34:38 pm »
I have tested the SNES with just 5V on the output of the regulator and it did not damage the regulator.  I got around 2V to 3V on the input of the regulator and distorted sound out of the SNES (the audio op-amps are run from the 10V input that is regulated down to 9V by the transistor).  I believe that the regulator has a built-in protection diode.  I don't think that there are many SNES's that have had the regulator fail due to a reverse voltage input.

Here is video of what it is doing.
 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #30 on: January 28, 2016, 02:18:19 pm »
Ok, I think this is where we stand currently:

CPU: Pass

WRAM: Pass

Data Bus: Pass

Address Bus: Pass

CIC (Lockout chip): Pass

APU (Audio Processing Unit): Pass

PA Bus: ?? <- probably ok but Yoshi's Island did not work so unsure

PPU1: ?? <- this basically loads the data into the VRAM (think shift register)

VRAM: ??

PPU2: ?? <- grabs data from VRAM and displays it

The start up logo looked mostly ok but it did display very slowly (as did the rest of the game as well as corrupted graphic tiles).

I would check the reset lines going to the PPU1 and PPU2 chips just to make sure they are working.  Keeping in mind that PPU2 sends out 2 reset lines of its own.  You could also try grounding one of the data or address lines on the VRAM chips with a 100 ohm or so resistor (or your meter on the ma range) and see what happens.  You can do this test when the cart is in the SNES and it is running.  You could also take the cart out and see if any of the data or address pins on the VRAM are being held high or low as that would indicate potential bad RAM.  This test may produce unpredictable results depending on how the SNES chips hold the VRAM in a reset condition.  I have attached a very simple test rom for you to use when you make a flash cart.  The made tiny one is for a hi-rom cart if that is what you manage to get to make your flash cart.  Make sure to copy and past any rom files you use to test if they are smaller then your eeprom or eprom chip until they are the same size as the chip you are trying to fill.  I recommend using notepad ++ and using s special copy feature so as to not introduce any extra data from the copy and pasting that may need to be done.
« Last Edit: January 29, 2016, 02:47:45 pm by poot36 »
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #31 on: January 29, 2016, 12:38:43 am »
Ok, I think this is where we stand currently:

CPU: Pass

WRAM: Pass

Data Bus: Pass

Address Bus: Pass

CIC (Lockout chip): Pass

APU (Audio Processing Unit): Pass

PA Bus: ??? <- probably ok but Yoshi's Island did not work so unsure

PPU1: ??? <- this basically loads the data into the VRAM (think shift register)

VRAM: ???

PPU2: ??? <- grabs data from VRAM and displays it

The start up logo looked mostly ok but it did display very slowly (as did the rest of the game as well as corrupted graphic tiles).

I would check the reset lines going to the PPU1 and PPU2 chips just to make sure they are working.  Keeping in mind that PPU2 sends out 2 reset lines of its own.  You could also try grounding one of the data or address lines on the VRAM chips with a 100 ohm or so resistor (or your meter on the ma range) and see what happens.  You can do this test when the cart is in the SNES and it is running.  You could also take the cart out and see if any of the data or address pins on the VRAM are being held high or low as that would indicate potential bad RAM.  This test may produce unpredictable results depending on how the SNES chips hold the VRAM in a reset condition.  I have attached a very simple test rom for you to use when you make a flash cart.  The made tiny one is for a hi-rom cart if that is what you manage to get to make your flash cart.  Make sure to copy and past any rom files you use to test if they are smaller then your eeprom or eprom chip until they are the same size as the chip you are trying to fill.  I recommend using notepad ++ and using s special copy feature so as to not introduce any extra data from the copy and pasting that may need to be done.

Rgr. I've been looking up test cartridges, but I still have no idea how to make one. All I can find is information about people using the official ones. How did you make yours?

I really appreciate the effort you're putting into helping me with this.
 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #32 on: January 29, 2016, 03:10:19 pm »
I made mine out of a cart with a dead rom chip.  I removed the rom chip and installed a socket (had to rewire the PCB because the rom chip pinout is different from a standard eeprom chip).  I used a old eeprom chip from a P2 motherboard and programed it with a eeprom chip programmer (a old Data I/O unisite from 1988 running software from 2006!).  Here is a link to the SNES carts rom pinout: http://www.caitsith2.net/snes/flashcart/cart-chip-pinouts.html and I have attached the datasheet for the eeprom chip that I used (the pinout on all standard 2Megabit chips should be the same).  I had to rewire 4 pins and disconnect the Write Enable (WE) pin on mine to get it to work.

So here is the list of things you will need:

eeprom chip

broken or cheap SNES cart

32 or 36 pin socket

eeprom programmer
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #33 on: January 29, 2016, 09:24:46 pm »
Thanks so much.

Is this the eeprom? http://www.ebay.com/itm/W29C020-90-DIP-32PIN-WINBOND-29F020-256Kx8-FLASH-MEMORY-/331761247120?hash=item4d3e82e390:g:FsgAAOSwoydWmB3O

Can I program it with a Pickit 2 or 3? I've been thinking about getting one, but I'm not entirely sure what they can do yet besides program some chips. I don't have a Data I/O programmer =/ Would I be able to perhaps use a breadboard, a 32 pin socket, jumper wires and the Pickit to program the eeprom? I've done that to program a few Atmega328s, minus the Pickit. I hope that doesn't sound too funny, but I'm a newbie who is delving into things way out of his league... but I'm determined and having fun.

Does it matter if the cart I use doesn't have the full amount of pins or will the eeprom still access the full features of the SNES hardware?
« Last Edit: January 29, 2016, 10:01:22 pm by Raellz »
 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #34 on: January 30, 2016, 03:30:26 pm »
Yes that is the eeprom but you do not have to get that one it was just an example.  The minimum size I would recommend getting is a 1 Megabit.  Just choose the cheapest one that is that size (or bigger) and has 32 or 36 pins.  The Pickit is for programming microcontrollers and serial eeproms not parallel eeproms.  Most (if not all) SNES carts should have the 36 pin socket but there are some games that have more then one eeprom chip in them and you want to avoid them as well as any carts that use an accelerator chip (eg Super FX chip, Mario chip) this carts have the extra two cart connector tabs on the bottom have a look at your Super Mario World 2: Yoshi's Island game for an example of this.  Just try and find a sports game they should be cheap.  Don't worry if any of your questions sound funny all of us were at that point sometime in our lives as well.  My re-programmable cart did not work first time either (I miscounted the pins and cut the wrong traces to rewire it!)  For the eeprom programmer I would look at Kijiji, Craigslist, or eBay just make sure it supports the eeprom you are trying to program.
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #35 on: January 30, 2016, 06:22:57 pm »
I'm looking at the TL866CS Uni Programmer and it says this

"The chip supporting range?
All kinds 26 27 28 29 37 39 49 50 Parallel ROM, EPROM, EEPROM" What is this referring to for compatibility?

After some digging I found this list http://www.autoelectric.cn/minipro/miniprosupportlist.txt which shows a huge list of compatible chips, yay!

It says the W29C020 is compatible, but the chip I was looking at has a -90 at the end and I cannot find that on the list. Does that matter at all?
 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #36 on: January 31, 2016, 01:48:35 am »
That programmer should work as long as there are drivers and software for you version of operating system on your computer and your computer has the appropriate connection for the programmer.  The -90 means the access speed of the eeprom chip.  It should work just fine at lower speeds as well.  For the SNES the high speed access is -120ns and low speed access is -200ns so this chip is faster then either of these speeds so it will work just fine.
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #37 on: February 01, 2016, 07:22:36 am »
That programmer should work as long as there are drivers and software for you version of operating system on your computer and your computer has the appropriate connection for the programmer.  The -90 means the access speed of the eeprom chip.  It should work just fine at lower speeds as well.  For the SNES the high speed access is -120ns and low speed access is -200ns so this chip is faster then either of these speeds so it will work just fine.

Thanks so much. I'm going to have to think if I want to invest into one of those so it will be a little while before I have any updates probably.
 

Offline poot36

  • Frequent Contributor
  • **
  • Posts: 434
  • Country: ca
Re: Super Nintendo - Unique problem
« Reply #38 on: February 01, 2016, 08:26:08 am »
I got my programmer locally (off Kijiji) for free.  If you wait you may be able to do the same thing.  Also check out any swap meets as well.
 

Offline Raellz

  • Contributor
  • Posts: 23
  • Country: us
Re: Super Nintendo - Unique problem
« Reply #39 on: February 02, 2016, 11:58:28 pm »
I got my programmer locally (off Kijiji) for free.  If you wait you may be able to do the same thing.  Also check out any swap meets as well.

Thanks I'll do that.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf