SNS-101 Voltage Regulator Issues

MNDudeMNDude
in Help Wanted!
I recently bought a SNS-101 that someone couldn't test because they had no power cable and I got screwed as the voltage regulator got completely stripped as it looks like they tried to remove it possibly. I got a new voltage regulator and I can only get the input to get 0.605v when I need at least 7.5v+ for it to output 5v. Does anyone know any other points on the board to attach the input and possibly the output? Thanks!

Comments

  • CZroeCZroe
    The 7805 has 3 legs:

    Input (I)

    Ground (G)

    Output (O)



    If you have a regulated 5V PSU you can remove the 7805 and connect 5V DC directly to the (O) point. Negative can connect directly to the (G) point. The (I) point would remain unused.



    I don't know if so would do this long-term but it will definitely let you test.
  • PikkonPikkon
    I traced it out for you,hope you get her working.

    https://i.imgur.com/dJGPsY7.jpg
  • MNDudeMNDude
    Thank you so much!
  • retroupgraderetroupgrade
    Quick question about the 7805: can you safely power logic chips from the output leg? I already have an LED on it, but would logic require filtering or a wide gauge wire?
  • CZroeCZroe
    Originally posted by: retroupgrade



    Quick question about the 7805: can you safely power logic chips from the output leg? I already have an LED on it, but would logic require filtering or a wide gauge wire?

    Yes, though there may be interference connecting to a modern switching PSU. A modern switching PSU is safer for testing (less likely to spike voltage before load; less likely to fail and output higher voltage to fry the chip).  If you check continuity all over the board with a meter you will find that +5v always has continuity to the (O) leg of the 7805.



    On a Hi-Def NES the kit takes over power regulation and the 7805 is removed. It powers the system through the CPU/PPU interposers so I routinely use the empty (O) hole for +5V (typically my power LED mod). This works because there is continuity between the interposer +5v and the 7805 +5v.



    There was an eBay seller I saw who connected his LED to the unregulated side (9v minus the rectifier voltage drop)!
  • MobiusstriptechMobiusstriptech
    Whatever you do, don't use a switching regulator for your SNES. Most of them do not behave properly and introduce excessive interference in the system. It will be noticeable in both audio and video. Stick to the standard 7805 linear regulator, but upgrade to a 2A. If for some reason you "need" a switching regulator, plan to spend more money on something really high end that doesn't have bad ripple and interference issues.
  • MNDudeMNDude
    I am starting to think that I cannot get a good enough of a connection on the ground pin either, anyone know where else I could ground it to?

    EDIT: The replacement regulator is from another broken SNES, they are the same value so no need to worry!  
  • MobiusstriptechMobiusstriptech
    You might want to post up some pictures. There are grounds all over the console. Use your multimeter to test for continuity between the ground pin of the 7805 and points on the board. Make sure the power is off and you don't have it plugged in, just to be safe.
  • MNDudeMNDude
    Finally realized I had a blown fuse (if anyone knows where to find a good replacement that would be well appreciated) so now the only issue I have is the ground having no connection.

    https://imgur.com/a/Dj7pP

    Sorry about the bad pictures, it is probably best that you can't see anyways :/
  • MNDudeMNDude
    IT'S ALIVE!

    https://imgur.com/a/sBUFh

    Thank you all for the help!  
  • CZroeCZroe
    Originally posted by: MNDude



    Finally realized I had a blown fuse (if anyone knows where to find a good replacement that would be well appreciated) so now the only issue I have is the ground having no connection.

    https://imgur.com/a/Dj7pP...

    Sorry about the bad pictures, it is probably best that you can't see anyways :/

    I'm actually waiting on an order with a replacement fuse for an SNES right now.   Glad you got it working!



    Console5 has them. If you got it working by bypassing the fuse I would definitely not trust that for too long! Order one anyway. They're cheap!
  • MNDudeMNDude
    Originally posted by: CZroe

     
    Originally posted by: MNDude



    Finally realized I had a blown fuse (if anyone knows where to find a good replacement that would be well appreciated) so now the only issue I have is the ground having no connection.

    https://imgur.com/a/Dj7pP

    Sorry about the bad pictures, it is probably best that you can't see anyways :/

    I'm actually waiting on an order with a replacement fuse for an SNES right now.  



    Console5 has them. If you got it working by bypassing the fuse I would definitely not trust that for too long! Order one anyway. They're cheap!



     





    I didn't bypass it, I used a bigger fuse that had the same rating (it's in the pic above) also thanks!
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