N64 RGB Mod - Poor quality image

Discussion in 'Modding and Hacking - Consoles and Electronics' started by fathertime, Jul 16, 2011.

  1. beharius

    beharius Resolute Member

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    I did the same mod, but wired the circuit to the mainboard directly, and removed all resistors and caps from the scart except the one in pin 18&20.
    Mine is a monitor, and it worked well for me. I am using a Vga to scart converter from Js technology. But yours is Viera with a built in tuner&scart. I read that problem before but forgot where I read...
     
  2. APE

    APE Site Supporter 2015

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    I modded a NUS-CPU-004 blindly for la-li-lu-le-lo. By blind I mean I cut traces, soldered wires and components without being able to test it myself.

    He found that so far that it works great with one caveat: the picture is a bit "neutral" in terms of picture quality and that with sound hooked it has what I'm interpreting to be "hum bars":

    I'm guessing it has to do with the RGB ground lines (all three have their own ground on pins 5, 9 and 13) wired with the audio ground causing a ground loop, hence the "hum bars". Probably can be fixed by removing the wiring to 5, 9 and 13 but since I've had to mod this thing blind I can't be sure. Shipping is gonna kill me if we have to play hot potato a few more times.

    la-li-lu-le-lo did want me to install discrete stereo jacks on the rear of the N64 which hopefully will negate any ground loop problems inside the SCART connector itself. What I'm wondering is if the RGB ground pins need to be grounded or will the cable function just fine without them?

    The picture I'm not sure about the problem of. I did wire in 75ohm resistors to each of the RGB lines but no capacitors as they were already present inside of the SCART cable. I'm wondering if the resistors were actually necessary or if the capacitors were necessary on the N64 end on top of those found inside the SCART connector.
     
    Last edited: Nov 24, 2011
  3. AlmostOriginal

    AlmostOriginal Spirited Member

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    Borrow thread

    [TABLE="class: inline"]
    [TR="class: row5"]
    [TD="class: col3"] Nintendo 64 Composite 75ohm resistor to ground on Composite Video and 220uF capacitor* in series is also recommended
    Nintendo 64 S-video 75ohm resistor to ground and 220uF capacitor* in series on Luma. 75ohm resistor to ground and 68nF capacitor in series on Chroma.

    *220uF capacitors are polarised, and it is important that the positive leg always goes towards the console and negative leg towards TV/Display.

    Could some one help me how i am suppose to wire according to description? A picture would be nice.
    [/TD]
    [/TR]
    [/TABLE]
     
  4. BlockABoots

    BlockABoots Gutsy Member

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    So i have a REV03 and REV04 US N64, i followed MMMonkeys internal amp mod aswell as the C-Sync mod, now both REV03 & 04 N64 work fine on my CRT TV via Scart Cable (im from the UK), but when i try the N64's on my Samsung LCD only the REV03 N64 gives me a display via scart but i am still getting a cross hatch display!!, and the REV04 N64 doesnt give me a display at all on the Samsung LCD TV.

    Instead of using having pins 3 and 9 linked via a wire on the mulitout pins should i use pins 7 & 9 then for both systems?...does this method actual add C Sync back to REV04 N64's?
     
  5. fathertime

    fathertime Rapidly Rising Member

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    You must link 7 and 9 with an added resistor instead of 3 and 9 in order to avoid cross hatch pattern on Samsung TV's. (uses c-sync instead of composite sync).

    REV4 has Svideo Luma sync on pin 7 that can be used instead of csync.

    (Edited an incorrect tech detail)
     
    Last edited: Nov 12, 2012
  6. BlockABoots

    BlockABoots Gutsy Member

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    Ah ok at the moment i have them just linked via a wire no resistor, what type of resistor do i need. I get a display on my CRT TV using the REV04 N64 but not on my Samsung LCD is this because i dont have a resistor between pin 7 & 9?
     
  7. fathertime

    fathertime Rapidly Rising Member

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    Follow this guide here:
    http://mmmonkey.co.uk/console/nintendo/rgbntsc.htm

    but linking Pins 7 and 9 instead of 3 and 9

    This method uses Svideo Luma for the sync instead of composite or c-sync.
     
  8. BlockABoots

    BlockABoots Gutsy Member

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    Is Luma regarded to be a better method of sync than composite then?, i take it that C-Sync is regarded to still be the best?
     
  9. APE

    APE Site Supporter 2015

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    C-Sync is pure sync from what I understand which makes it better than using a video signal for sync. A sync stripped will take composite and make a nice sync signal roughly par to that of C-SYNC.
     
  10. BlockABoots

    BlockABoots Gutsy Member

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    Thought as much. In regards to gaming on a CRT display would using a C-Sync method display any improvements in picture quality over composite or Luma?, or would it only really make a difference if using an LCD (digital) display?
     
  11. FireAza

    FireAza Shake! Shake!

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    Here's the method I used to RGB-mod my French N64, it works and looks perfect:
    [​IMG]
    (small red line is a cut trace)

    I've modded 2 N64s with this method, and it works fine. I imagine a US N64 would be exactly the same, though with different resistors possibly.

    *EDIT* Hmmm, images don't seem to be loading ATM...
     
    Last edited: Nov 12, 2012
  12. fathertime

    fathertime Rapidly Rising Member

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    You only need to use luma for sync line if using a samsung TV but it looks perfect on a CRT too. Samsungs give the crosshatch pattern using composite or the c-sync line for sync
     
  13. Bad_Ad84

    Bad_Ad84 The Tick

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    Csync worked fine on my samsung too btw. Only reason I use luma is because its available on all consoles with no hassle.
     
  14. BlockABoots

    BlockABoots Gutsy Member

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    Apparenty you can still get C-Sync for NTSC REV04's!!

    OzOnE told me how, you need to bridge pin 9 and the via of 'R16' which is located just south east of the MultiOut pins!! This will add C-Sync back to REV04.

    Thank OzOne for this!!
     
    Last edited: Nov 13, 2012
  15. Bad_Ad84

    Bad_Ad84 The Tick

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    its much easier to connect to luma thats like right next to it, with the same results.

    I never said csync isnt available, just luma is easier and the same.
     
  16. BlockABoots

    BlockABoots Gutsy Member

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    Ok understood
     
  17. hugocraft

    hugocraft Rising Member

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    The n64 I had growing up as a kid is alive again since I picked up an everdrive 64 and so now wanting to add RGB to it so I can use the n64 with my SCART to component converter since the genesis looks great using RGB-SCART cable for the genesis. I got the n64 console when it first came out in the states so I bet its mod'able for RGB but I'm still hesitant since its my original one. Kinda tempted to try it on a capable console off craigslist.

    Is amplifying the RGB using the THS7314 chip the best way to mod a n64 for RGB? I hope so since I already ordered the chip! I'm in the USA so its all NTSC but was wondering will I still be able to use the stock composite cord? Also will it be necessary to do step 2 in the quoted post above with cutting a trace and jumping pins with resistors?

    Also for step 3 where should I order the PAL SNES RGB scart cable?

    Thanks for any help since I'm a noob :D
     
    Last edited: Jan 14, 2013
  18. hugocraft

    hugocraft Rising Member

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    Any advice?
     
  19. CZroe

    CZroe Rising Member

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    I think you might also be able to see the dithering more easily. The N64 dithered a lot! It was much better than slowing things down for a higher color mode.
     
  20. Bad_Ad84

    Bad_Ad84 The Tick

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    Yes
    No
    Yes
     

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