N64 RGB mod having issues

Discussion in 'Retro & Arcade' started by Vanne, Dec 15, 2021.

  1. Vanne

    Vanne Member

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    So i installed my latest RGB mod (tims board) onto my newly aquired Jap N64 the other day, ive installed a few of them now, but this one just doesnt seem to wanna play ball.. i get horizontal rolling of the crt when its powered up. ill take a few pics to let you see what i mean, but its anoying the hell out of me, ive dubble checked all my solder points and traced the wires.. just cant seem to get this one to work properly.

    on my crt it rolls, on some of my flat panels it just comes up with "mode not supported" ... crazy...

    i thought it might have been down to the SNES rgb cable i was using from retrovision, but after closing j1, j2 and J3, still no cigar.

    its got me stumped...
    IMG_20211214_175927.jpg IMG_20211214_170840.jpg IMG_20211214_175315.jpg IMG_20211214_180125.jpg IMG_20211214_170940.jpg

    Watch full eyes will note I haven't connected up earth on the board to the heatsink, but I've ran that wire before, makes no difference.. maybe my Retrovision cable scrapes the sync from the signal, so I've ordered a el cheapo one. Will see if that does the trick.. if not.. back to the drawing board and may just sub out another one of Tim's boards..
     
    Last edited: Dec 15, 2021
  2. elvis

    elvis Old school old fool

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    If there's a recognisable picture but it just rolls, it means hsync is good but vsync (within csync) is bad.

    I'm not familiar with these boards, but just sanity checking: you've got a wire soldered off CS# (assuming this is TTL sync) not CS75 (assuming this is composite video level sync). Was that intentional?

    Likewise ground isn't connected, although I'm assuming you've got a common ground somewhere else.
     
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  3. MUTMAN

    MUTMAN Member

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    Wasn't there two versions of the DAC ??
    The mod has a second chip for one of the differing stock arrangements ??
     
  4. Grant

    Grant Member

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    Looking at the install guide, that's what the adapter PCB on the DAC chip does - converts it to the "DENC" pinout: http://etim.net.au/n64rgb/instructions-new

    I'd triple check for continuity and shorts between the adapter PCB and the chip's legs, it's not completely in focus in the photo.

    The red wire for sync doesn't look like what the install guide says to do, could you explain your working there?
     
    Last edited: Dec 15, 2021
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  5. OP
    OP
    Vanne

    Vanne Member

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    Ehh.. yep,!!

    Grant, i soldered this puppy up after a long ULR flight, that would be the reason.. holy shit, i didnt even catch that.

    ill reverse the sync and see whats what..

    Elvis , yeah its grounded on the back of the board, no issue, again.. as grant also pointed that out.. i didnt even catch it.. holy shit..

    thanks guys, ill reverse it after a few good night sleeps...

    can you say...
    dumbass.jpg
     
    Last edited: Dec 16, 2021
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  6. MUTMAN

    MUTMAN Member

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    far out eagle eyes there :thumbup:
    nice detective work there people :)
     
  7. OP
    OP
    Vanne

    Vanne Member

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    Just revisiting this, as i havent mucked around with it after posting about it. ill remove the CS# cable and see how we go. Thx again Grant, i got no idea how/why i soldered that up.
     
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  8. OP
    OP
    Vanne

    Vanne Member

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    Rejigged the wires, dubble checked the connections. I am going to put this down to a bung board.. :(
     
  9. Grant

    Grant Member

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    That sucks to hear, have you contacted etim? He might be willing to do testing on the Altera chip.
     

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