Mega Drive 2 RGB/60hz Confusion.

Discussion in 'Sega Discussion' started by MentalMan, May 10, 2009.

  1. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Hello there, ASSEMbler user's. Have been lurking around since quite a while now, finally having a good enough reason to sign up, being in need of some good insights.

    The story is, that I have a problem with my Mega Drive 2 and TV. A while back I did the good old 2 Switch mod, turned out really well even though it was my first time at soldering. (So, i bought all the necessary equipment for a reliable mod just for the little 16 bit baby. The tutorial was MMMonkey's, everyone should have had a glance at it by now to know what I am talking about.) I also did a paint job, I always wanted my MD2 to look like Dreamcast. Anywho, I finally had bought myself an expensive RGB-SCART cable for the system, and what do I have to see when I turn it on, switches flipped to NTSC? Black and White! I felt like I narrowly avoidet a signpost up ahead and entered the twilight zone. (again.) I was pretty crushed and disappointed, I had been pushing all of this Tale for long enough because I dont like throwing cash around since there's too many other expenses that need taken care off.

    Now, I am aware that being in eurotrash Pal territorys, using an old Phillips tube TV, (Here's a cheesy "manual" btw. It also states fully RGB wired.) that there could be problems with it accepting the 60Hz signal, it being 50hz. But the thing is, i've never had this problem. I've had a rgb scart for Ps1 (and later the same one used on ps2) for ages, happily playing away NTSC and PAL. Dreamcast also does 60hz on it. As well as a moddet xbox1. (for saturn and snes I am unable to tell, both unmoddet.) So I do think this tv CAN do the beauty of 60hz, fullscreen and vibrant colors. No twilight there. (Or is there?)

    So what is it with my MD, could it be the Cable? Or is the refreshrate just somewhat "different", or odd for the TV in this case? I only have another HDTV in the house, and this one gives me more confusion. Here's the story for this one *sigh* (I know, its an annoying long read I suppose.)

    Quite a while back, a tryed out my old ps1 on the HDTV (With RGB cable) out of curiousity to see how shit it really looks. Well, I got a hell of a trip seeing rainbow colors all over the screen, the RGB colors that is. Pretty messed up, I have not enough knowledge about "normal" TV's (me loves my desktop TFT's at a good refreshrate.) to understand what the hell was going on, I figure since its again phillips, and pal territory tv, something's just lacking... (In this day and age, pff.) I dont know. Maybe somebody here can tell me. (I dont have the model number right now.) Oh and btw, the HDTV has 2 scart ports, One is labeled RGB, ironicly enough, and this is the one with strange colors, the other one is obviously not RGB supported and shows a B&W picture. After that i tryed out my unmoddet (well, sort off. Softmod) Ps2 with harddrive, turned on the horrible Initial D (is it 2? i dont know which one.) and it was a normal picture. Pretty ugly of course, but colors. Come to think about it, I never did try my xbox1, but then again, i only have the pack-in cables for it :S

    So today I tryed out the MD2 with RGB cable on HDTV after the Tube and damnit, it gives the same issues ps1 did. Does it not support proper 60hz for crying out loud? (Again: Ps1 60hz with RGB on my old tube, where MD does not work, DOES work.)

    So, I dont know really know what else to say. Please make a conclusion of this whole text ridden mess. I dont understand it, if my old tube TV does not support 60hz. Then why does it work with "everything" else going 60hz thrown at it? A freaking mistery to me.

    On a addet side note, the lady I got the cable from, (ebay) does loads of them and was pretty much my only source for one, she said in a very friendly reply, that it could also be my MD mod? Is that correct? I kinda doubt that, I didnt do anything with the video connections or did I? All the mod is about is grounding and giving +v5 at two points.

    No going crazy with super sonic through action replay 2 at 60hz with RGB picture and moddet MD for me, *sniff*. Dirty whore, after all i did! If anyone is curious, here's a few pictures of the aforementioned whore, show yourself to the internet you bitch! (Im sorry, haha, I just dont know what else to do, really pissed me off earlier today.)

    Pic1

    Pic2

    The pictures are shit too, you can barely make out the type of switch I used. Not sure right now, what its called in English. But i just call it a whipswitch, that'll be a rough translation. Though it sounds kinda "rough" ;) Personally I think it looks way better then those most of the time used dildo switches, i just dont like'em! Also mind that after the pics I fixed the few ugly spots like the case not going down completly on the switch side.

    I hope anyone can explain me what is going on. I have never encountered 60hz issues before with anything else as mentioned. Excuse me again for the long writing, maybe some can get a mildly entertaining story out of it how 20 year old friends can betray a 20 year old friend, or maybe its just the TV that is being the bitch in this game. The thing is, I dont really have any other options. Cant (Dont want to as well.) buy an expensive "new" tube TV just for that, neither a cheap one without knowing a hundret percent, that it will work.

    Well, thanks in any case, I'd be grateful for any tips. Supposely I will get a straight out answer that neither of the TV's in this household will work haha.

    Oh and Ps. Please feel free to move to a more suitable sub forum, i wanst completly sure if its MD/Sega releated, TV releated or both at once. So i just picked this one :shrug:
     
    Last edited: May 10, 2009
  2. TmEE

    TmEE Peppy Member

    Joined:
    Aug 13, 2008
    Messages:
    362
    Likes Received:
    1
    your problem is, that you don't end up in RGB mode, the TV still seems to look the composhit signal instead of the RGB ones... if RGB ones would be functional, you'd not get B/W image. There's one pin that needs some power to be applied to it (I don't remember which one, you need a ~150ohm resistor too).
     
  3. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    So what you are saying is, that the Cable is missing an resistor? It is not the TV then?

    Incidentially, I had the cable cracked open and its 8 wires. However glued in place, Im not sure if i have seen a resistor.

    On Here in one of mmmonkeys other guides, about making a RGB cable for MD2, it shows a 100ohm resistor.

    Im really confused, so what, i gotta get that glue off and fix the cable myself? :S Well that is just tops lol, that ebay chic also said she tested every cable she sends out and had it tested on a pal and ntsc unit, supposely working. Scammed?

    Bah.

    edit: i can try to make a picture if its worth anything?
     
    Last edited: May 10, 2009
  4. TmEE

    TmEE Peppy Member

    Joined:
    Aug 13, 2008
    Messages:
    362
    Likes Received:
    1
    BTW, do you plugged the cable into the SCART slot that accepts RGB on your TV ? My Philips has 2x SCARTs, but only one accepts RGB.
     
  5. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Yes, my Philips has fortunaly only one Scart slot, and that is supposed to be RGB wired.
     
  6. MottZilla

    MottZilla Champion of the Forum

    Joined:
    Feb 1, 2006
    Messages:
    5,066
    Likes Received:
    102
    From the wiki:
    Pin 16, the blanking signal pin, carries a signal from the source that indicates that the signal is either RGB or composite.
    0 V–0.4 V means composite.1 V–3 V (nominal 1 V) means RGB only.Also, maybe on your TV there might be an option to force RGB perhaps?

    http://en.wikipedia.org/wiki/SCART
     
  7. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Thank's for the info MottZilla. Sadly no, the RGB seems to be auto-controlled. And it looks like, the power to send the signal is missing?

    Quite odd. Can anyone maybe explain me, why the HDTV gave a messed picture, with both MD under RGB, and Playstation 1 under RGB? colors where indeed present, however just messed up, like a rainbow overlay.

    And the ps1 does work under RGB on the old tube tv. So it all comes closer to the MD2 RGB cable dosnt it? I'll add a picture later on, maybe its of some interest. If not, i have to study this situation and try to fix it myself?! :(

    edit: Sadly i am unable to take a decent picture but i exposed the scart plug once more, and there are indeed resistors hidden beneath the sperm, ehm, i mean glue. Curious..

    edit2: fascinating, looking at my open Ps1 RGB cable, Pin 8 and 16 are connected with each other through a resistor. Thank goodness there is no glue obstructing the view. Pin 8 also recieved a wire. Wherein 16 did not. Only the resistor goes to that. This is a witch hunt!

    Incidentally, has anyone tips for removing glue? I presume its odd hotglue, but im not sure. I'd like to have a good look at the MD RGB cable's wiring.
     
    Last edited: May 10, 2009
  8. TmEE

    TmEE Peppy Member

    Joined:
    Aug 13, 2008
    Messages:
    362
    Likes Received:
    1
    for the glue, try to heat it up with something, then you can start removing it when its soft enough.
     
  9. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Yea, i'll give that a try later on. Without being able to see how it is wired up, I'll never get a clue what's really wrong :(
     
  10. Codeman

    Codeman GasPanic bouncer

    Joined:
    Mar 29, 2007
    Messages:
    428
    Likes Received:
    0
    The rainbow effect seems to suggest that the blanking pin isnt getting enough juice.

    First remember to select the proper AV channel on your TV.

    Get a multimeter/voltmeter and see how much juice is getting to pin 16/8.
    If these pins are not bridged together then try bridging them.
    Also those mini-din plugs cand be a bit dodgy, check if the plug is properly inserted in the Megadrive and twist it a bit to see if there are any pins making a dodgy connection
     
  11. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Thank you for the suggestion, this could very well be the cause, at least from a logical standpoint. Still havent got myself over at facing the glue, but I gave your other ideas a try.

    The AV channel is selected 100% and shown in the corner of the screen.

    After connecting it all up, I tryed twisting and slowly reconnecting. The connections plug wise where sturdy. When I stuck in the mini-din plug into the mega drive and twisted it, it made no difference. All tight. After disconnecting and reconnecting it slowly, the sound came first in and after a milimeter more the picture appeared but not the one im looking for.

    Sadly I do not own a multimeter yet, so that's no go.

    The next step would be to check out 16/8 and if it is bridged.

    Does it make a difference if one of the wires from the cable goes to pin 8, or to pin 16? Regarding this point I am confused, looking at the obstructed view there might as well be nothing connected to one of the bridged points.

    Also, what ohm resistor should I find bridged. 100ohm, or 150ohm? TmEE, you mention 150. Not that I trust the MMMonkey guide more, but he seems to use 100ohm. Any explanation is highly appreciated =)
     
  12. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Bah. Got most of the glue off nice'n clean, enough to have a good look.

    Here's how the pinout looks, underlined and bolt mean's it has a connection to something, if not, its blank.

    |\______________________
    |19 17 15 13 11 9 7 5 3 1 |
    |20 18 16 14 12 10 8 6 4 2|

    Upper row: 15, 11 and 7 seem to be RGB. All with their little blue resistor.

    Lower row: 20, 6, 4 have wires attached. Now the weird part, 18 and 2 are bridged together. Just bridged, I dont see anything in between, its a little solid piece of metal. Would have come out of a bigger wire. No copper either.

    16 and 8 seem to have been bridged by a resistor, I guess its 100ohm, have to check up with their stripe coloring.

    Well, that's what I gathered so far, really freaking annoying. And compared to MMMonkeys MD2 scart guide its wired differently.

    :(

    edit: I have noticed I made a mistake, the odd bridge from 2 to 18 does have a wire attached. White, with a green stripe. After the wiki entry Pin 2 is "Audio Input (Right)" So that one takes care of one of the stereo sound wires. But for 18 it says: "Composite video input ground (pin 20 ground)". Do I even want/need that? Why is 2 even bridged with that? Oh my oh my.
     
    Last edited: May 12, 2009
  13. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    What the hell is going on :-(

    I did a couple of changes and it's still not doing it. I changed the grounding bridge from 4 to 17 (Before 4 to 18.) like in MMMonkeys tutorial out of curiousity (The only source I have anyway.) and that didnt change much. So I bridged 17 with 18 as well like my ps1 RGB cable (With a piece of wire) and no dice. I also changed the (supposely) ground wire from the cable from the ground bridge to pin 4. (before it was attached near pin 18 on the bridge.)

    All of that and few other look-over's havent changed anything.

    Now here is the really weird thing.

    I accidentally pushed the Videotext button on the TV and what the hell? There's color! If the videotext is activated while using the AV Scart port, the picture just darkens usually and P100 is shown on the left corner of the screen, the videotext page.

    But in this case, it gives the picture color and makes it look good, but darker as well as being in videotext mode and having annoying numbers on the screen. The picture also shifts a bit to the left thanks to the videotext.

    Here's a couple of pictures to illustrate what is happening:

    | Color | No Color |

    With color = AV in videotext mode
    Without color = normal AV.

    I really dont understand what is going on and I dont really know what else to try...

    The resistor stripe color is btw: Brown - Black - Red - Gold. Not sure if I am correct, or made a mistake with the colors. Wouldnt that be 1kΩ 5%? My ps1 RGB cable seems to use a 75'one.

    Anyone, please help! I am getting clueless.

    edit: Oh yea, I forgot to mention that for a split second there's color when switching the channel away from or to AV. I can also repress 0 to "reload" the AV channel and for a split second there's color and then it switches back to ugly.
     
    Last edited: May 14, 2009
  14. Codeman

    Codeman GasPanic bouncer

    Joined:
    Mar 29, 2007
    Messages:
    428
    Likes Received:
    0
    Have you bridged pin 16 to 8 yet?
    You can leave the resistor bridge there but you should try a direct bridge.
    Try bridging them , I made a paperclip bridge for my white Saturn.
    Faster then soldering a piece of wire, just cut the paperclip and bend it like this |_| and then it should fit and snap-in nicely in the pins without any soldering required.

    The teletext thing is normal, when the TV is getting some signal through RGB and you open the teletext it will show whatever is plugged in to the scart, even if the AV channel isn't selected.

    Btw do you have anything else plugged to the 2nd av port of your tv? If so unplug it.

    To sum it up, so far you only got a b/w stable picture and you have to manually select the AV channel, right?
     
  15. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Interesting! No I havent tryed anything like that, so far just the resistor is doing a bridge from 16 to 8. I'll give that a try later, thanks!

    I see, and no there is currently nothing else plugged in the TV, just the MD scart cable.

    That is correct. I suppose it would make sense that the 16/8 bridge dosnt have enough juice to manually enable the RGB. Its funny that the picture is super sharp and nice with the teletext thing activated. Does this suggest that the TV in Teletext mode in some way acts with RGB and/or activates it for the use with the teletext? What a tease.

    Thank's again! I'll report back how the changes work out.
     
    Last edited: May 15, 2009
  16. Oldgamingfart

    Oldgamingfart Enthusiastic Member

    Joined:
    Jun 24, 2008
    Messages:
    509
    Likes Received:
    2
    Yes the Text module is usually switched on the same RGB line as the SCART socket(s), by the TV's micro. There's only one RGB line inside most TV's with each RGB source then switched along it (a bit like railway tracks).

    Are you sure you don't have any S-Video options on that SCART socket as that may disable RGB and give a B/W composite pic. Failing that, why not try and run the RGB through a DVD recorder as it might be more forgiving?

    *EDIT* Reading back it does sound more like a switching problem, and pin 16 is the key here.
    I wouldn't bother with pin 8 for now, just connect directly to pin 16 (with the resistor) and manually go to the A/V input to see what happens. You really need a multimeter though as I have a feeling you have no switching voltage coming from the MD at all. This would explain why the TV doesn't:

    a) autoswitch to SCART
    b) change to RGB mode.

    If the above test fails you have no switching voltage from the MD and the cable is faulty. You can verify this with a simple test by attaching a 9v battery to pin 8 of the SCART plug. Do this by first disconnecting pin 8 wire coming from the MD (leaving the resistor and bridge from pin 8 to pin 16 in place).

    With the TV on in tuner mode (normal viewing), plug the SCART lead back in the TV and place the - of the battery (the larger terminal) onto the outer metal shield of the SCART (or pin 21 as its called), and the + terminal onto Pin 8. The TV should switch over to A/V (on some TV's when you apply this you will get an RGB striped band across the top of the black screen when in A/V mode).
    If the TV doesn't switch try the - terminal from the battery onto pin 18 instead. Now turn on the MD and you should have an RGB picture (well, until the battery goes flat sometime in the future!)
     
    Last edited: May 16, 2009
  17. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    Oh that's a lot of nice information. :)

    So what I could try is ignoring pin 8 and just doing pin 16? Interesting, for the time being that would be something to do. Btw currently the Wire for switching goes to Pin 8 after my documentation, I did try to switch it over to 16 once but that just gave a blank picture (however sound was present.).
    Before the wire was going directly to the resistor leg that would then proceed to go into pin 8...

    The battery thing sounds like a great idea as well, I will definitely consider giving that a go and see what happends. I guess that would be the last resort without a multimeter at hand.

    @Codeman, I tryed doing a paperclip bridge leaving the resistor in place as well. It just gave a blank picture again, with sound present. (If i switch channels, it just stays black as well, not even showing numbers and icons.)

    Thank's so far, the next steps i'll try will be yours, Oldgamingfart's. Let's see what happends next lol.
     
  18. Oldgamingfart

    Oldgamingfart Enthusiastic Member

    Joined:
    Jun 24, 2008
    Messages:
    509
    Likes Received:
    2
    Yeah just go for pin 16 first as that's the one that'll tell the TV to go into RGB mode, if that fails try the battery test.
    FYI, pin 8 just switches the TV over to A/V and bypasses the TV's own tuner (AFAIK), so if you're already on the A/V input you don't need to worry about it for now.
    Anyway see how you get on. I'm confident you'll be able to sort it out in no time :thumbsup:
     
    Last edited: May 17, 2009
  19. Christuserloeser

    Christuserloeser Rapidly Rising Member

    Joined:
    Jul 27, 2006
    Messages:
    90
    Likes Received:
    5
  20. MentalMan

    MentalMan Spirited Member

    Joined:
    May 9, 2009
    Messages:
    110
    Likes Received:
    0
    lol that is exactly the one that gives me all the troubles, plus it's shoddy work. There's even stuff that came loose the very first time, just by looking at it. If even I can do a better scart solder job then who did these, Chinese kids? :confused:

    Haha, thank you for your confidence. Havent had time to do anything yet but I am eager to, I cant be too far away from solving it once and for all, plus the whole wiring will be more sturdy then before :lol:
     
    Last edited: May 18, 2009
sonicdude10
Draft saved Draft deleted
Insert every image as a...
  1.  0%

Share This Page