N64 RGB Mod - Poor quality image

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

  1. Segata Sanshiro

    Segata Sanshiro speedlolita

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    That's much much worse than my day 1 soldering..
     
  2. brainpann

    brainpann Site Supporter 2012

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    Yeah, it makes me feel loads better about my first soldering attempt.

    It kind of looks like they held a lighter to the solder and hoped for the best. :)
     
  3. io.

    io. Member

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    I saw you were talking about this special N64 FRA which can be easily modded. Here is what I've done with the only two I own.

    This is my first N64 FRA modded to RGB. It was my first attempt to solder SMD. Parts were taken from a really dead SNIN.
    [​IMG]

    Since I did this mod, I have received the missing components but they're not soldered yet.

    This is my second N64 FRA modded to RGB, better isn't it ? :)
    The second picture is the inversion of CIC chips (I have taken out the european CIC and put an japanese CIC instead). Now this N64 can play NTSC games in RGB.
    [​IMG]
    [​IMG]

    Now, some pictures showing differences between RGB and composite. They weren't taken under the best conditions.

    First pic is for composite and the second one is for RGB.

    NTSC US
    [​IMG][​IMG]
    [​IMG][​IMG]
    [​IMG][​IMG]
    [​IMG][​IMG]
    [​IMG][​IMG]

    NTSC JAP
    [​IMG][​IMG]
    [​IMG][​IMG]

    PAL
    [​IMG][​IMG]
    [​IMG][​IMG]
     
    Last edited: Dec 1, 2011
  4. bennydiamond

    bennydiamond Gutsy Member

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    Hi, I'm new here and I recently attempted the RGB mod using the TI's amp on my moddable NTSC-U N64. I have an earlier revision which have C-SYNC routed by default. I wired the RGB, C-SYNC and GND to a GBS-8220 (cga2vga upscaler).

    I do get an image but it's in grayscale... I tried to hook the upscaler on both my LCD HTDV and my LCD VGA screen but same result in both cases. I tried both PAL and NTSC games with my everdrive.

    I should point out that I live in Canada. It 's probably a region compatibility thing. I know RGB is a PAL standard but won't the GBS-8220 get rid of this problem and output a true VGA signal?

    I don't know what to do... I'd like for this to work. The upscaler works fine, I tested it using my dreamcast hooked to the VGA port.

    What can I do to make this setup display colors?

    Thanks!
     
  5. brainpann

    brainpann Site Supporter 2012

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    Hmmm, the first thing I would look at is the R and the B (red and blue) lines going from your N64 to the scalar. It sounds like those signals aren't getting to the scalar. Do you still get full color when you connect to a TV using regular composite cables? If so, it may be the way you have the RGB connected, specifically the R and B.

    Well, if you have an RGB capable NTSU N64 (nus-cpu-003 or 004), it doesn't matter. NTSC N64 games should play fine and in full color.


    Have you tried a regular cart(not the everdrive)? Is it still in BW?
     
  6. bennydiamond

    bennydiamond Gutsy Member

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    Thanks for the suggestion but none of them could resolve my issue...

    I still get full color image on composite cables (while scalar is still plugged on). I am sure that all 3 color signals are getting to the scalar. I tried removing them plug only one at a time. I get an image with an overly colored tint corresponding to the signal. Only blue signal connected gives me a blue image, etc.



    Can anyone confirm they do have a RGB modded NTSC system hooked on a NTSC TV, playing NTSC-U games and everything works? Does anyone in America tried this mod and are playing NTSC-U games? I think it's a CIC chip thing.

    I tried 2 original carts. No colors on RGB but full color on composite.

    I also tried to use the composite video signal as the sync source instead of C-SYNC but that didn't help.
     
  7. brainpann

    brainpann Site Supporter 2012

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    Yes, I have done this mod to three different ntsc n64's with much success. :)
    They work great on my NTSC tv.

    Ok just to confirm, are you using the ths7314 amp? If so, I would

    1) check that the ths7314 is wired correctly.
    2) check that you are using the correct resistors/capacitor
    3) if you have another ths7314, try wiring it in instead

    How did you go about connecting the n64 to the scalar? Did you hack up a scart cable or something else?
     
  8. Lum

    Lum Officer at Arms

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    Something has gone wrong then. N64 like most Master System or newer consoles, is RGB based. It's the system's raw internal format. Encoding colors into NTSC or PAL happens later.
     
    Last edited: Nov 6, 2011
  9. brainpann

    brainpann Site Supporter 2012

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    After thinking about your problem, bennydiamond, I am inclined to think it is the amp itself. I inadvertently switched the ground and 3.3v wires on the amp once and afterwards the color was never right. It always looked as though the red and blue were crossed. I spent a few hours trying to figure out why the hell the colors were wrong until finally I just replaced the amp with another and things were fine.

    If you don't have an extra amp or just want check to see if that is even the problem, you can just wire the RGB lines directly to the corresponding pin on the AV port (or whatever your cable from the scalar goes to). Results vary with this technique but you should get a color correct picture. More than likely the picture will be too dark, hence the amp. Sometimes people report a picture that is too bright. If that is the case, you can try adding some resistors. Regardless, doing this should let you know whether the amp is busted or not.
     
  10. bennydiamond

    bennydiamond Gutsy Member

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    Hi, sorry for the late reply. I have connected the scalar straight to the RGB points and I do get colors!!! As expected the picture is rather dark. I received tofay a replacement amp, I will replace the faulty one.

    One question remains though. Am I using 30 AWG gauge kynar wire. Is that too small for this kind of signal? Is R,G and B signals 1V max? If so that means there is roughly 27 mA running through each wire maximum (taking into account the 75 ohm impendance). Is that too much? I don't think so.

    One last question. What is this fuss about using the Luma signal for sync? If my picture was looking good using C-SYNC without any amp on the color signals, is it worth it to use Luma? What is this X pattern I keep reading about. I want to get the best image quality possible and I don't want to open up my console over and over again!

    Thank you all for your help!
     
  11. Bad_Ad84

    Bad_Ad84 The Tick

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    X pattern happens when using composite video as sync source. C sync should be fine, it worked for me when composite video gave x pattern
     
  12. beharius

    beharius Resolute Member

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    Once upon a time, I modified my N64 JP(rev. 03) by Waltarzar's method.
    http://mmmonkey.co.uk/console/nintendo/n64rgbbooster.htm
    I didn't solder the circuit into the scart cable instead inside the console and used a scart without resistors nor capacitors.
    It was fine, probably better than composite. However I wasn't satisfied with the graphics and sold it to someone else here. Now I am thinking of trying this THS7314 IC method. Is it a big improvement over the old one? Or no hope, continue to play on Xbox?
     
  13. seanami

    seanami Rising Member

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    I am having trouble finding the parts for the capacitor and resistors on digikey. Is there specific ones that you would recommend? Or some specs that I should look for. Only know 75 ohm resistor and 0.1 uF capacitor, but no other specs for them.

    Thanks
     
  14. bennydiamond

    bennydiamond Gutsy Member

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    Those are DigiKey part number.

    0.1uF Generic decoupling capacitor : 478-5741-ND

    75 Ohms 1% tolerance 1/8 watts : RNF18FTD75R0CT-ND

    You could probably go for 0.1% tolerance resistors but those would be much more expensive. I'm sure everyone can agree that 1% resistors are sufficient.
     
  15. seanami

    seanami Rising Member

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  16. APE

    APE Site Supporter 2015

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    The amp mentioned in this thread is a lot smaller than I had anticipated making it very difficult to mount on any sort of strip board without modifying it, carefully.

    For the sole job I've done so far (currently untested due to lack of a SCART capable TV) I ended up soldering the capacitor directly to the VCC and VSS pins, flipping the whole thing upside down and wiring it into the N64 atop a bed of electrical tape. Upon finishing I covered it with another piece of electrical tape similar to the method mmmonkey used on his guide. There isn't much room inside the N64 under the shielding so you do need to be careful not to build something too tall. Unlike mmmonkey I soldered my 75ohm resistors directly to the solder pads on the MultiAV connector rather than directly to the amp itself. Seemed to be a more solid connection but seeing as I cannot test my work at this time there may be unforseen consequences with placing them further away. I doubt it, but you never know.

    Some questions I have (because unfortunately page 1 of this thread is a bit confusing):

    1) C-SYNC (pin 14 on the N64 DAC) is unbuffered and apparently shouldn't be used as such. What is the danger of using it unbuffered? I'm assuming it could potentially destroy the DAC through unforseen problems such as static.

    2) After decoding the values link83 posted for the unpopulated portions of the PCB involving C-SYNC I'm confident I could wire in through hole versions without too much trouble (all I have on hand). The only part I cannot figure out is the transistor. Any idea what it might be or an equivalent there of?

    3) PAL SCART cables are expecting a sync signal on pin 9 of PAL N64 cables. On NTSC consoles pin 9 outputs composite video. Cutting pin 9 off from composite video and wiring C-SYNC to pin 9 is a good idea. Correct? (this is using what I'm assuming to be an unmodified SNES PAL SCART cable)
     
  17. bennydiamond

    bennydiamond Gutsy Member

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    For the pcb I would suggest one of these : www.ebay.com/itm/2X-SOIC8-SOIC-8-Ad...288?pt=LH_DefaultDomain_0&hash=item415307f3a0

    you can also do it like APE and place the IC in a dead-bug position and solder straight on it.

    As for the C-Sync stuff APE, it is correct what your are saying. Cut trace of the composite video and bridge C-SYNC to it. There are also some good result using the Luma signal of S-Video ( labeled L) with a 75 ohms resistor in serie with your sync output pin (9). I am using C-sync and it works great, no need for Luma.
     
  18. sanni

    sanni Intrepid Member

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    I need your help please. :crying:

    My N64 is a NUS-001(JPN) and my TV is a rather old 42" Panasonic Plasma with a resolution of 1024x768.

    The image quality is good, considering it's just a plasma screen:
    [​IMG]
    [​IMG]

    But the image is shifted to the left:
    [​IMG]

    The N64 was modded by wolfsoft.de long long time ago. The only thing I changed is that I added the two 75 Ohm resistors. But that didn't help much.

    This is the complete pinout of the cable and the console itself:
    [​IMG]

    Does anyone have a clue what I could try?
    Thank you very much.

    Edit:
    Using Luma + 75R as sync results in the same shifted image as C-Sync (+-75R)
    If I take Composite Video as sync then the image has the already known net overlay effect, which looks really terrible BUT is is perfectly in center position.
    The image is more stable(up/down) without the 75R.
     
    Last edited: Nov 23, 2011
  19. beharius

    beharius Resolute Member

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    You can adjust the horizontal positioning from the menu if it's a th42pwd series.
     
  20. sanni

    sanni Intrepid Member

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    I have a TH42PX80 and I can change the position only for things plugged into the VGA port and not for scart. I just wrote a mail to Panasonic maybe they can help me.

    I also tested the official PAL Gamecube RGB cable. I had to remove the 75R that bridges Sync to Ground to get a stable image and since it uses Composite Video as Sync the image is perfectly centered.

    But again there is the checker board/net pattern, it's not as noticable like with the other RGB cable and sometimes it even seems to vanish. Maybe the 220uF capacitor in the sync line of that cable filters it out a little.

    So to sum it up:
    - C-Sync as sync signal = image shifted to the left side
    - Luma as sync signal = image shifted to the left side
    - Composite Video as sync signal = image perfectly centered but checker board pattern
    - 75R between Pin 20 and 18 of the scart plug makes vertical think very bad, so remove it

    GC RGB cable
    [​IMG]
    75R
     

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