SNES black screen only when powered.

So, I wanted to get in some time on Super Castlevania. Pulled my system out of its storage box, for a whole lot of nothing.... Cleaned the pins allowed dry time, still nothing. The LED shows power when on, but once you flip the switch the screen flashes to black silence. I bought this system new in 1993. Other than the expected yellowing, has been well cared for. I last used it thanksgiving of 2016 was working great then. I keep it wrapped in a large cloth, and in a Styrofoam clamshell case I got from a local stores produce department.
So, that breaks down useage, and storage if that info is relevant. In my research I have been seeing that a particular motherboard has been shown to fail over later revisions. That is of course the SHVC-CPU-01 variant. That they are doing the same thing mine does, and is likely irreparable. However, even though I have a SVHC board. It's an SHVC-CPU-02. I have yet to find any info on this particular revision to know if it has the same failure points of the first boards. Google came up empty searching for that revision. Provided is a Pic of the board, if you need a close up of a particular chip let me know.
Thanks for any suggestions, and help!

Comments

  • It's rare, sometimes it is simply the power supply. Try a different one. I've had one system over the years that it worked on.
  • I'm going to a local retro game shop to pick up another one. Will try the a/c adapter from the one I pick up. If that works I will have a spare system. The SNES is the only system I don't have a spare of. Never thought I'd need one....
  • There are a lot of early SNES boards which inexplicably work with RF but not composite. I'm still trying to figure this out!
  • Hmmm, well, I feel dumb now... Never thought of the RF output to test if it was indeed working. Thanks for the heads up. But, my old RF module is absolutely worn out, it outputs a dirty signal no matter what you do. It got pinched under my bulky entertainment center from the CRT days. Hasn't been any good since. You would think as long as I've been gaming I'd have 100s of them... No, just the one that came with my NES.
  • Well, it won’t technically “switch” anymore, but you can get away with a shielded RCA cable and one of these:

    image



    Who uses an antenna anymore anyway, right?  
  • Originally posted by: CZroe



    There are a lot of early SNES boards which inexplicably work with RF but not composite. I'm still trying to figure this out!





    I have a board that outputs black and white with composite but full color with rgb or component,changing the video encoder had no effect.
  • Originally posted by: CZroe



    Well, it won’t technically “switch” anymore, but you can get away with a shielded RCA cable and one of these:

    image



    Who uses an antenna anymore anyway, right?  



    this diagram/picture confuses me..  should the ones under the text not be used or the ones being pointed to? wait, both coax and rca are pointed to.... so..  hdmi?

     
  • Originally posted by: rokubungi

     
    Originally posted by: CZroe



    Well, it won’t technically “switch” anymore, but you can get away with a shielded RCA cable and one of these:

    image



    Who uses an antenna anymore anyway, right?  



    this diagram/picture confuses me..  should the ones under the text not be used or the ones being pointed to? wait, both coax and rca are pointed to.... so..  hdmi?

     



    Use the one in the top 2 images. One end is female RCA. The other is male F-type coaxial RF (with the stinger).

     
  • i have about 15-20 snes' i've collected over the years that have this issue.



    is there a way to maybe convert them to hdmi and get them to work?
  • Unfortunately, the drastically different SNES configurations and the way the chips are packaged makes it extremely unlikely that anyone will make a proper HDMI kit for SNES. The person who'd best be able to made the Super Nt instead.  
  • Originally posted by: CZroe

    Well, it won't technically "switch" anymore, but you can get away with a shielded RCA cable and one of these:

    image



    Who uses an antenna anymore anyway, right?  






    Oh, I use one of those for my Atari 2600, and 5200 systems. That adapter works well with the old systems, should work just as well on the SNES. A friend of mine offered me his system with all the hookups, and some games on the cheap, so either way will finally get to gaming.
  • I do kinda worry about using it with systems that have an automatic RF switch since there is a bit of extra power on the cable to power and trigger the automatic RF switch. Even so, I hear from a lot of people using it just fine, so I didn't hesitate to suggest it.



    NES, SNES, N64, GameCube, Master System, Genesis/Megadrive Model 1, TurboGrafx-16/PC Engine, etc all do this with the extra power. Their respective RF switches filter this so it never gets to the TV. No concern for stuff with a manual RF switch like Commodore VIC-20/64, Atari 400/800/XL/XE, Atari 2600/5200 (2-port)/7800/2600 Jr, etc should all be fine.



    The 4-port Atari 5200 also carried power over the RF lead but it went the other way and actually powered the console! Ultimately proved to be ill-conceived but it's the one I use.  
  • That I didn't know, but am glad you said something. I wouldn't worry about the tank of a CRT I use for classic gaming. But, will think about it before using any of those systems via that adapter on my HD panels.



    I have one of the early 5200's with that annoying RF +power in one unit systems. Haven't powered it on since the mid 90s, that stupid RF module is floating around here somewhere. They are never in the same space at the same time. I use a later 2 port model much simpler.
  • Well, my first SNES is dead tried a new power supply, both composite, and RF. Only a small green bar blips on screen for a split second. The LED isn't on now, but the screen go's from static to a black screen.

    I got another to replace it today it came with A Link to the past. I had never seen this particular label variant before. Only the one like on the left in that pic. The system I got is yellowed exactly like my old one. So much for switching out case parts. Don't guess the retro brite trick works on these since it is more of a chemical reaction of the plastic composition versus age?
  • Originally posted by: Nes Freak

    Even with the right revision, not all of them have the same encoder chip capable of the component mod.  

    Originally posted by: Yellow355F1>
    Well, my first SNES is dead tried a new power supply, both composite, and RF. Only a small green bar blips on screen for a split second. The LED isn't on now, but the screen go's from static to a black screen. I got another to replace it today it came with A Link to the past. I had never seen this particular label variant before. Only the one like on the left in that pic. The system I got is yellowed exactly like my old one. So much for switching out case parts. Don't guess the retro brite trick works on these since it is more of a chemical reaction of the plastic composition versus age?

    All yellowing is a chemical reaction. Too much bromine (flame retardant) in the mix + UV = reaction with the plastic.   I've brightened them successfully but they are still really brittle. Don't put any solution on the power and reset buttons even if they are discolored beccause it'll screw up the lettering.



    Someone borrowed and never returned my K-A Player's Choice Million Seller variant and I replaced it with an E for Everyone Player's Choice Million Seller. As a result, my box and manual don't match.  



    I also have a really late non-Player's Choice Million Seller E-rated Super Mario World. Really weird that it doesn't have the gold PC ribbon.
  • My guess would be a dead cpu.
  • Originally posted by: CZroe

    Originally posted by: Nes Freak

    Even with the right revision, not all of them have the same encoder chip capable of the component mod.  

    Originally posted by: Yellow355F1>
    Well, my first SNES is dead tried a new power supply, both composite, and RF. Only a small green bar blips on screen for a split second. The LED isn't on now, but the screen go's from static to a black screen. I got another to replace it today it came with A Link to the past. I had never seen this particular label variant before. Only the one like on the left in that pic. The system I got is yellowed exactly like my old one. So much for switching out case parts. Don't guess the retro brite trick works on these since it is more of a chemical reaction of the plastic composition versus age?

    All yellowing is a chemical reaction. Too much bromine (flame retardant) in the mix + UV = reaction with the plastic.   I've brightened them successfully but they are still really brittle. Don't put any solution on the power and reset buttons even if they are discolored beccause it'll screw up the lettering.



    Someone borrowed and never returned my K-A Player's Choice Million Seller variant and I replaced it with an E for Everyone Player's Choice Million Seller. As a result, my box and manual don't match.  



    I also have a really late non-Player's Choice Million Seller E-rated Super Mario World. Really weird that it doesn't have the gold PC ribbon.





    Don't see that particular chip on my board. But, the SHVC is laid out different than that GPM model shown.

    And, that is what it was the flame retardant is the culprit on the yellowed plastic. I had seen a discussion about it a while back, but had forgotten that was the issue.

    I remember seeing the players choice games on the shelf back in the day. Didn't know the carts had gotten a new look also. Man, I don't even want to get into the whole mistake of loaning games.....
  • Originally posted by: CZroe

     
    Originally posted by: Nes Freak

    Even with the right revision, not all of them have the same encoder chip capable of the component mod. 



    i thought the RBG encoder just requred extra components.

     
  • Originally posted by: Nes Freak

     
    Originally posted by: CZroe

     
    Originally posted by: Nes Freak

    Even with the right revision, not all of them have the same encoder chip capable of the component mod. 



    i thought the RBG encoder just requred extra components.

     

    That would probably be part of an RGB bypass, which may be what they do in the video since I can tell from the thumbnail that it’s not a component-capable SHVC with the modular SPC700. Guess I should’ve watched it first, huh?  



    The usual SNES component mod taps into the capability of a particular S-ENC encoder (normalizes RGB and outputs composite, S-video, component, and RGBS). The RGB bypass with component replaces the later, less-capable, encoder chip with one equally capable.
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