Menu

Sega Genesis Model 1 – RGB Bypass – Best way to lift pins on the 315-5313?

Home Forums Repairs and Mods Sega Genesis Model 1 – RGB Bypass – Best way to lift pins on the 315-5313?

This topic contains 9 replies, has 2 voices, and was last updated by  nzChris 3 months, 3 weeks ago.

Viewing 10 posts - 1 through 10 (of 10 total)
  • Author
    Posts
  • #24116

    cheeseman
    Participant

    Hi there,

    I’m looking into doing the new version of voultar’s RGB board that was just released. It’s going to go in one of my VA3’s or a VA6 I have.

    What I’ve noticed is that there isn’t really a great updated tutorial on this – retrorgb has warnings all over their Sega RGB pages saying to hold off that an update is coming, and the guide on here is good, but doesn’t lift any of the pins on the 315-5313 and some other info that is somewhat conflicting.

    I’m going to start small and basically rig up this RGB amp with the least amount of cutting traces and etc, check for jail bars and go further if needed.

    Assuming that the best way is to completely lift the RGB and CSYNC pins right off the 315-5313 (i’ve read that some people still had jailbars until they completely bypassed the traces)

    How would you recommend lifting the pins? I really don’t want to damage any of the nearby pins – do i heat up the end of the pins with a soldering iron then lift them with a pin? Maybe cut the pins off the bottom with an exacto knife? Maybe its safer just to cut the trace in a way that it can be repaired easily?

    Thanks,

    #24215

    nzChris
    Participant

    Here you go! 4 hours of install haha, around 33 mins in what you want.

    #24261

    cheeseman
    Participant

    Thanks for the info about the 33 min mark, 4 hours is way to long for lifting pins.

    I think I will just prep the board for now and wait.

    #24740

    cheeseman
    Participant

    Well, I got all the pins lifted off the VDP without issue (nerve racking lol)

    I followed the steps here – as I also have a NTSC VA3

    http://www.twipu.com/retr0drift/tweet/1074627860529217536

    It syncs up with the OSSC and plays fine, but It just looks odd. Pretty much exactly what my other VA3 (with just pin 50 cut/composite) so it still has some vertical lines and blue seems a bit funky.

    I am nabbing the 5V from the 7805 regulator, but I ran the ground to a common location. I’ll try moving that over to the regulator as well.

    @nzchris – sounds like you spoke with voultar in another post – do you think cutting pin 50 might do the trick?

    Also I am running Revision 2 of the RGB amp.

    #24742

    cheeseman
    Participant

    I just realized that I soldered directly to the pins on the old 8 pin DIN.

    I’m guessing there is tons of interference coming back in from whatever is still hooked up to it ?

    #24753

    nzChris
    Participant

    Yes I would absolutely recommend you lift up pin 50, that is what made mine look perfect from being a mess before.
    If you still have issues after this maybe look at snipping the legs on the CXA1145 (20/21/22/10).
    Good luck! it really is worth it, I have been playing my Megadrive constantly since I got this working, especially good with the OSSC and turning on scanlines = )

    #25004

    cheeseman
    Participant

    I was able to lift pin 6 on the CXA chip which goes to the VDP pin 50 and it resolved the funkyness

    Its odd though, it still has the same kind of vertical lines here and there, but I don’t think they are jailbars.

    I think it has something to do with sampling phases as I am just using the default settings and going though all the line x modes when testing.

    It is 100% slightly different than my other VA3 without the mod, but I can’t say that it better. Just different. Are the colors slighty sharper? maybe? etc

    Regardless thanks for the help – running the 5V to the regulator and grounding it closeby helped alot + with the pin 50 lifted.

    #25043

    nzChris
    Participant

    Hey there,

    You describe the same experience I have here. With the OSSC you can clear the image up by enabling the Low Pass Filter. Play around with the LPF in the output? and sync menus and you should find a combination that works.

    * Have you followed the OSSC optimal tuning YouTube video? HIGHLY recommend you do so if not!

    With regards to I’d there an improvement I’m starting to think it is sideways. I bought a job lot of Mega Drivrs so I have a few to test. Here is a photo I took yesterday of a stock MD1 with NTSC mod. And then a MD1 with bypass.

    View post on imgur.com

    View post on imgur.com

    Maybe I haven’t chosen an interesting background but I’ve decided I prefer the darker green on the stock image. The bypass board green I a bit more yellow.

    With the bypass you can see some extra colours on Sonics head.

    What do you think? I should try take some shots of other games to compare again.

    Chris

    #25047

    cheeseman
    Participant

    I thought I was alone in this – but that pretty much sums it up

    I will load up the OSSC optimal timings and take another look. I have a feeling from that it’s just a few tweaks and they will most likely go away. I remember watching a Firebrandx video, where he had the lines I was talking about in some RPG game, and then he changed the sampling and it was gone.

    Awesome job on the screen shots. Its a very close call as well but sonic does have different colors on his head for sure. Not sure which one is better. (I think with these things you have to see them in person)

    Not sure if you have an everdrive (or the game itself), but I find the best way to find these lines are on “Dr.Robotnics mean bean machine” (or the puyo puyo game it was basically made from)

    At the main menu: https://www.mobygames.com/game/genesis/dr-robotniks-mean-bean-machine/screenshots/gameShotId,37625/

    The brown area on that menu screen shot is just a mess with these vertical lines.

    I’ve only ever put the bypass on a NTSC VA3. I also have a VA6 I might drop it on. I am always just a bit worried about lifting the pins. No so much about breaking them ( you could always sand down the chip at the edge for a 2nd chance) but still – there is always a risk.

    One other thing I will note, is that I put the RGB board where the RF adapter used to sit. (removed the RF adapter as it was broken) I know you had put it on the VDP, but I was planning on putting a M1 Mini Mega audio amp board there.

    #25055

    nzChris
    Participant

    I think I need to do the test again but directly into my TV SCART connection and look at it objectively without the OSSC making it pretty. I think the real question is, did it fix the jail bars? the brighter colours it seems are more of a preference thing and you could probably tweak the OSSC to do this anyway.

    Yeah I have an Everdrive so I will load that game up and give it a test later too.

    I have 11 PAL Mega Drives high def and non, mostly Chinese, two made in Thailand and one Japanese PAL (All modded to NTSC), I will do some more comparison this weekend.

    Yeah I remove the RF adaptors off all of my Mega Drives to mount a region switch there, no need to drill extra holes everywhere plus it’s only hipsters that would want to play through RF lol.

    Never heard of this audio amp before, my understanding is if you have the Yamaha YM2612 you have good audio and the models with the YM3438 are the ones that need a replacement. Might pay to find out which sound chip was used for the before example.

Viewing 10 posts - 1 through 10 (of 10 total)

You must be logged in to reply to this topic.