Sega Megadrive (Genesis) Black Screens & French RGB (1601-09) 

I figired out about the sync signal for the regular mega drives . Just solder composite sync (purple cable) to the other purple cable and separate it from the transistor like you awrady did . You can amke a switch to choose between 2 nodes . Be prepared to have issue wirh the green coil next to the IC. I come address 2 units with this coil goes defective. It become a resistor and very hot . There is a way for this too. Change it , but it can eventually fail again in the future. So make a switch for VDD pin (orange cable) to choose between 12V produced by this IC when the coil is ok, and 5V. When this coil goes bad the IC can not otput 12V animore , but about 5 , 6 and there are very bad interferes on the screen . If you completely remove this coli the IC will no produce any output voltage and TV will not turn automatically in rhe SCART RGB mode , but this is not a rpblem , becouse you can do this manually via the TV remote control. This is a easyest variant if you wish . About that 5V and 12V to pin 8. 12V are to force TV to switch 4:3 and 5V is to switch 16:9 . But you can always do it manually like above situation.

I have French Sega how to run it with the regular SCART RGB cable? I do not have this special one with the PCB. :(

Through some research (Sega Retro mostly), the Mega Modem port was removed and the video encoder is through-hole, so the board's a VA6.5. The final revision Europe got was 6.8, where the encoder is surface-mount. Yes, I know this video is super old and crusty.

Shit you find in Megadrives... I was given an ASIAN PAL-B that had the RF unit inside with the wir coming through a small hole on the back. The RF unit was velcro'd down. The power unit was soldered to the main board

Where can I get the HI-LO probe you used to mine CPU data?

Mmm i got an exact same type of revision board, with the weird resistance soldered on the 68k pin... but mine its not even producing any sound. When powered on it sends a black screen to tv, and thats all...i've resoldered all major components (68k, z80, ram, vram, cart slot, ym2612, sony cx...) how can i diagnnose whats happening?

So glad I found your video, I just brought a 'working' Mega Drive from eBay but when I switched it on it had a blank screen. I followed your tip regarding cleaning the cartridge port...and...it now works perfectly. Awesome, Thanks!

Thanks GadgetUK. A week ago I found a cheap Megadrive for 17 pounds. I had to buy a PSU and the Scart cable. So today I've opened the Megadrive and there was some rust (the board came from the UK). There were some places where I wasn't sure if there was continuity in the traces. So I did just like you do, used the fiberglass pen with IPA and all of the traces came to shinny copper again but one of the chip under the cartridge port; the third pin on the left. Lucky that I've seen your video as I see that it isn't connected although the trace gets very near it, but it doesn't connect to the chip. At the end I used nails lacquer to protect the board. I think that I should search for something better. Another thing: Just opening the case, trying to unplug the cable from the power led, the pins broke on the board. I see that you leave the cable connected, but it's a pain if you want to clean the case and the board. I soldered two pins to the mobo and now I can plug and unplug that cable.

hello what is the name of the pen you use in the video to test the processor of the mega drive? what's the name of this tool?

Hi, any advice where to get that scheme that you showed in the vid?

Hey mate, the "WTF" :) mod on pin 6, is on the Address Strobe output signal. On boards where they used the MC68000 they had to add the resistor to limit the current else I believe you get a crashing issue after it has been powered up for a while. I guess it must be a bad combination where other chip(s) are drawing more power on the Address Stobe than the MC68000 is rated for per pin

I am looking so hard for a picture of the underside of a SECAM megadrive and you talk about it for like a full minute but never show the bottom of the board :(

To convert you could get sync directly from the VDP like some RGBS Sega bypass boards. A standard console also has a resistor and capacitor connected to digital 5v on the sync line so you might want to recreate that.

My HDG VA6 Genesis runs fine with Genesis games, however when I try to get a 32X game to work, I just get a black screen. I also have tried my SegaCD2 and it won't power up with the Gen1. My VA3 and VA1 Gen2 models will run the SegaCD2 and 32X with no issues. I have cleaned every console connectors/ribbons, so cleaning is not an issue. I think there is something wrong inside the Gen1 console, but I don't know where to look.

@GadgetUK164 Hey, many many thanks as you got me motivated to fix my 2 french MD (I'm french so ~~). Dry/broken solders on cart port for the 1st one was the issue. On the 2nd one, I can't really tell : random black screens when "cold", it will sometimes freeze on some games (like Earthworm Jim, Sonic 1/2/Knuckles running flawless), no issues when "warmed up". I re-did some solders, global visual inspection but can't find any clue (the random phenomen not helping). Otherwise, except beeing "rare" what's the point of having those 1601-09 ? I'd consider sell one and get back a "standard" MD but I can't really find any reason to do so ...

The revision was on the board. Under IC4 there were two lines with two numbers followed by VA5 and VA6. The number corresponding to whatever is printed on IC4 tells you whether it’s a VA5 or VA6. Basically, this board was designed for the version of IC4 with the integrated TMSS boot ROM but they still had a bunch of the old non-TMSS chips on hand. They clearly designed the board to accommodate either. It is a VA5 or a VA6 based on whatever populates IC4. There are VA5/6 boards in every region.

Is the 32X fix only for the PAL VA4?

Hi! My name is Carles. Firstly, sorry for my English is very very little :-(. I need help. I have two Megadrive first model but they have a problem. They have blackscreen. I cleaned the cartdridges and the slot one hundred times. I don't know to do. I need help. Thanks.

I want to talk about contacts in a key or in this case in the Reset button. My reset button wasn't working so I unplugged the rubber globe around the reset contact button. I cleaned the inside with IPA and Deoxit and then I tried again the reset button, but it didn't work. Then I used a "Lakier grafitowy" kit that I bought time ago that uses graphite, but after applying it and leaving it in the sun to dry for several hours it didn't work. So I just cutted a tiny piece of desoldering copper wire and I glued it there. Now the reset button is working perfect and I think that it will work there forever now ;)

Early Mega Drives don't have the license screen when you turn it on. It was an attempt to copy protect their systems. From what I have read it didn't take much to get around it. I think only a few games don't work with that protection. Do you know which version of the Mega Drive was meant to be the "best"?

You say that you "oiled" the volume pot and also the switch behind it. I cleaned with Deoxit the volume and I also applied the same grease you use to use to the plastic rails, but it doesn't work perfect. I'm scared about using oil, can you tell what did you do exactly?

French consoles really are the PAL units to search out as they invariably support RGB scart.

Recently I've been searching for information on Mega Drive/Genesis OEM SCART cables. I found an article that showed how to modify the French RGB cable to work with PAL and NTSC TVs. Apparently the cable uses a unique type of sync designed as a workaround because SECAM TVs didn't use a composite signal thus making sync-on-composite impossible. The article is in French, but I was able to use Google Translate to read it. Here is a link to the article: www.segakore.fr/index.php/2004/08/07/mega-drive-modifiez-votre-cable-rgb-fr-vers-pal-ntsc#.WWBj4IpumRt

I have the model 1601-09 but i haven´t the 3085. There is possible one mod or to make a cable in this model? Thx!

I've also got a French RGB model, VA4 main board but I get a black screen and no sound on headphone jack. Sometimes I've got a constant glitched sound but it's really rare. I've cleaned thoroughly the cartridge connector and tightened the pins to no avail. However, I don't see the resistor on the M68000 leg and there's no visible corrosion on the solder points or pcb tracks (there's some on the EXT connector). Do you have any suggestions?

Can you turn the console to 60hz

I have a pal va4 megadrive that is ntsc but will only play the region free games I have until the finish of the opening logo. Spinning espn etc. No modifications done to it and playing a pal game I get no picture or sound. Really confusing.

Great Video mate, I'm in the same predicament, been playing around with the same unit and to no avail have re flowed cart joints cleaned and re tensioned, have also checked voltage on 6800 z280 and VDP all have 5 volts, have even removed resistor on pin 6 thinking it was a hack mod, my unit has rf and rgb via scart with comp video sync tried both no good! , have checked continuity on all IC'S no issues. Maybe the CX1145 might be ratsh1t I have a logic probe and would be willing to test the pins on the 6800 and any other ic if needs be, but have bugger all knowledge on what I am doing, is there a link you may know of that can show me what each pin is supposed to be outputting, or can you suggest the best way about attacking this. Any help would be appreciated cheers franky

My megadrive is full of patch wires and all sorts of weird stuff and it is supposed to be stock. I reckon the early models - mine is - needed some patching and working on to become stable. Excellent video as usual. You make stuff like this seem easy. Well at least it encourages a guy like me to try my hand at actually modifying and repairing my systems as well.

My sega genesis (megadrive) gives me just a blank black screen when i turn it on, do u know it could possibly be? It has been in storage for 20 plus years and it used to work fine, any tip u can give me?

Can i made s-video mod for this model?

Just going by the location for the region and hz jumpers, the RGB board looks to be a va6

You made me open up my Mega Drive!!! I have a VA4 too, doh I wanted a 32X soon too. My VA4 was manufactured in May 1992 and doesn't have that resistor on the chip near the cart slot. Very interesting, that in the space of 2 weeks between that being made and mine, they must have sorted out what that resistor was doing. I think mine went through some sort of quality testing as a number of the chips have coloured wax crayon on it. I have owned this from new and never opened it.

great stuff, thanks for the informative videos. i have a couple of megadrives that are getting power but have a black screen. Ive cleaned the cart slot and re-soldered the underside of the slot but i still get a black screen. do you have any advice for further troubleshooting? i have a multi-meter too. thanks..

Mine is totally bugged