Hey,
I just picked up a Nintendo Super System, and it has a problem where when first turned on, it comes up with a gray screen, and then it eventually (after 10-30 mins) fades into the normal screen. It's definitely the PCB and not the monitor. I'm very surprised that I can't find any info on this as it seems to be a REALLY common problem.
[backstory]
I first saw it this summer when I was helping w/ the CGE arcade machines. It worked when I tested it at the warehouse, but when we got it to the show, I thought that machine was broken. While I was trying to troubleshoot it, someone walked by and said that it was normal, and his machine does it as well. He said to just leave it, and eventually it'd start working (I though "yeah... sure"
). So, I left it, and about 30 mins later I walked by and it was up and running.
[/backstory]
So, my new one does this, though just slightly different (this becomes visible within a minute or so, but stays washed out for quite a while, and occasionally snaps in and out).
Now... looking at the MAME source, I see info about a fix for various video and sound problems. But, I can't find ANY info about this mod except from MAME. I would have expected someone to have posted this somewhere, which would have caused the MAME guys to add it in... but it seems like either the MAME guys figured out the mod and just put it in the source, or the place that they got it from is long gone.
Does anyone know about this mod? Is it meant to fix the gray screen problem, or something else, or is it a hack that's gonna fry the system?
Or does anyone else even have the gray screen problem?
Thanks,
DogP
I just picked up a Nintendo Super System, and it has a problem where when first turned on, it comes up with a gray screen, and then it eventually (after 10-30 mins) fades into the normal screen. It's definitely the PCB and not the monitor. I'm very surprised that I can't find any info on this as it seems to be a REALLY common problem.
[backstory]
I first saw it this summer when I was helping w/ the CGE arcade machines. It worked when I tested it at the warehouse, but when we got it to the show, I thought that machine was broken. While I was trying to troubleshoot it, someone walked by and said that it was normal, and his machine does it as well. He said to just leave it, and eventually it'd start working (I though "yeah... sure"
[/backstory]
So, my new one does this, though just slightly different (this becomes visible within a minute or so, but stays washed out for quite a while, and occasionally snaps in and out).
Now... looking at the MAME source, I see info about a fix for various video and sound problems. But, I can't find ANY info about this mod except from MAME. I would have expected someone to have posted this somewhere, which would have caused the MAME guys to add it in... but it seems like either the MAME guys figured out the mod and just put it in the source, or the place that they got it from is long gone.
Nintendo Super System modifications
This describes main board modifications which corrects some
various video and sound problems on the NSS-1 version main PCB.
on the solder side of the main PCB:
-------------------------------------------------------------------------------------
Remove R101, R71, L55, L56
-------------------------------------------------------------------------------------
Solder jumper across L55 and L56 (shorting L55 and L56 independently)
Approx a 5" jumper wire from R101 (solder pad closest to C181- where
the below resistor will be) to the leg closest to R68
-------------------------------------------------------------------------------------
insert a 10 Ohm, 3 watt resistor on parts side of PCB between
C9 and C10
-------------------------------------------------------------------------------------
Volume control: 10KOhms
Sweeper --- pin 25
Ground ---- pin 26
Signal ------ pin c (opposite of pin 25)
-------------------------------------------------------------------------------------
CN2 pins 8 & 9 to pin 24
CN2 pins 4 & 5 to pin "b" (opposite of pin 24)
Does anyone know about this mod? Is it meant to fix the gray screen problem, or something else, or is it a hack that's gonna fry the system?
Thanks,
DogP

