nfg.forums

NFG Forums => RGB + Video Discussions => Topic started by: scarmullet on March 17, 2013, 06:45:43 AM

Title: N64 RGB mod help
Post by: scarmullet on March 17, 2013, 06:45:43 AM
I am working on an N64 RGB mod using the THS7314 chip as an amp. I am not using SCART, but I am using a custom cable I built for my SNES, so that I can use it with my CGA to VGA adapter, (the one found in the DIY scaler kit). There is a problem, the image is too bright for my tastes, so bright it washes out the image of any detail.

I think the culprit may be the 220uF caps I have on my custom cable. What do you think?

Title: Re: N64 RGB mod help
Post by: scarmullet on March 17, 2013, 06:56:49 AM
Sorry for the double post, but here is a better example from Super Mario 64 that shows how bad the image is washed out.

(http://imageshack.us/a/img268/940/sunp0006.JPG)
Title: Re: N64 RGB mod help
Post by: ApolloBoy on March 18, 2013, 03:46:37 PM
Do you have 75 ohm resistors on the output pins on the THS7314?
Title: Re: N64 RGB mod help
Post by: scarmullet on March 19, 2013, 06:16:11 AM
I do have 75 ohm resistors on the AMP.
Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 10:35:35 AM
Your machine was already RGB modded?
Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 10:41:53 AM
If yes, it is possible that you got a internal booster tweak to burst a little the rgb output.
check in this page: http://www.eurasia.nu/wiki/index.php/N64RgbBooster (http://www.eurasia.nu/wiki/index.php/N64RgbBooster)
look at the bottom of the page.
If there, remove it.

For the THS7314 amp the 220micro farad are perfect.
Title: Re: N64 RGB mod help
Post by: scarmullet on March 19, 2013, 11:30:28 AM
I did the RGB mod myself.
Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 11:40:30 AM
mmm...
Did you respect the polarity of the caps?

Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 11:51:56 AM
this is what i did, maybe it can help you....
Title: Re: N64 RGB mod help
Post by: scarmullet on March 19, 2013, 11:52:33 AM
Yes. I am using the same cable I made for my SNES to pull RGB off it, and thats fine. Positive towards console.

I had initially soldered the RGB lines right to the chip, I moved them to the bottom holes and then touched up the pins on the chip, that way they make a solid connection, and it helped a little bit, but after a while video blinked out of the system, Composite, S-Video, and RGB...gone.
Title: Re: N64 RGB mod help
Post by: scarmullet on March 19, 2013, 11:55:53 AM
Quote from: unshe on March 19, 2013, 11:51:56 AM
this is what i did, maybe it can help you....

the wire joining 7 and 9, is that for a proper Cync instead of C-Sync?
Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 12:00:54 PM
This board is REV-04, so no proper CSync in pin3.
I'm using Y "Luma" as source of Sync instead of CVBS (composite-video). This help whit LCDs for better quality.

The Blue wire give 12V to pin 3. So i use a gamecube Pal cable.
Title: Re: N64 RGB mod help
Post by: unshe on March 19, 2013, 12:02:06 PM
Quote from: scarmullet on March 19, 2013, 11:52:33 AM
Yes. I am using the same cable I made for my SNES to pull RGB off it, and thats fine. Positive towards console.

I had initially soldered the RGB lines right to the chip, I moved them to the bottom holes and then touched up the pins on the chip, that way they make a solid connection, and it helped a little bit, but after a while video blinked out of the system, Composite, S-Video, and RGB...gone.

Are you still hearing sound?
Title: Re: N64 RGB mod help
Post by: scarmullet on March 19, 2013, 12:22:09 PM
Yes I am.
Title: Re: N64 RGB mod help
Post by: unshe on March 20, 2013, 03:33:40 AM
check the pin of VDC-nus you restored.
Try removing all the ampli mod e check if Videocomposite is still working.
Title: Re: N64 RGB mod help
Post by: scarmullet on March 20, 2013, 06:15:39 AM
Quote from: unshe on March 20, 2013, 03:33:40 AM
check the pin of VDC-nus you restored.
Try removing all the ampli mod e check if Videocomposite is still working.

I tried and broke off pins on the VDC...I assume it is dead.
Title: Re: N64 RGB mod help
Post by: unshe on March 21, 2013, 01:11:59 AM
Not good.
Can you make a very good picture of the VDC?
Title: Re: N64 RGB mod help
Post by: scarmullet on March 21, 2013, 06:19:16 AM
Not really, the board is scorched under the top two pins on the right side.
Title: Re: N64 RGB mod help
Post by: unshe on March 21, 2013, 08:00:43 AM
If you want you can send me the machine, i will try to fix. Of course for free....
Title: Re: N64 RGB mod help
Post by: scarmullet on March 21, 2013, 08:23:05 AM
Nah thats fine. All I need is a new VDC chip, right? Desolder, clean up the pads, solder new one on, wham bam, thank you ma'am
Title: Re: N64 RGB mod help
Post by: unshe on March 21, 2013, 10:22:58 AM
Good luck!