Ask general Genesis/MD/Sega CD/32X questions here (for new members)

[serbusfish]

I have a model 1 PAL Megadrive that has an overclocking switch so the console's cpu can run at 10mhz. Today the console froze up on me when playing Thunder Force IV, and obviously this isnt ideal. I was thinking the power supply could potentially be the cause, the one I have is not an official PSU, its one of those replacements from amazon and runs at 9V, but I know a 10V PSU will also work with the Megadrive. Could the lower voltage perhaps be causing instability when in overclock mode as I have never had any consoles freezing issues when in standard mode? Ive also never had problems using these replacement PSU's just to clarify.

[majinga]

No, 9V are ok to feed the voltage regulator. But the PSU can be still be the problem. Check how many amps it can handle. Or directly try with another one. You can also check the PSU with a multimeter to check if it is alive. If you have no voltage it is dead, otherwise you have to check it with a load, better a load who match the MD (for example the MD ).

The mod also can be the problem, but start with the easy task. Check the PSU first. You must go for steps to solve the problem.

@superfry63
Good job with your Saturn. I'm still not so lucky with mine .

[Blast]

Hello!

I've got a couple of PAL Model 1 Mega Drives, one working and one... kinda-sorta not (it's very strange but for now just assume it'll boot for five seconds then crash). I'm 99% sure the working on is a VA6 while I'm not sure what the non-working one is. Working on is a non-HD Model with TMSS, broken one is a HD Model without TMSS. I've got a third-party power cable that seems to work fine and a third-party RGB Scart cable (one of the fancy ones with a headphone jack).

The actual issue, then, is quite the bit odd, and I'm not sure yet what the cause is but I *think* it's my TV. I caught a video of it since it's sort of hard to explain, sorry for the low quality, I don't have a better way of recording it.

The issue itself seems to be something to do with the blue, after a bit of messing around with TV settings and things such as the seperate RGB boosters (Red and Green get affected normally, Blue is barely touched). A thing to note is that this happens on both Megadrives, only in Sonic 1 and 2 (it doesnt happen in Knuckles or Spinball, my other two games), and it doesnt happen on a different TV. So I'm a bit confused, since if it was a TV issue you'd think it would happen in Knuckles and Spinball too (and wouldn't have the brief spurts of working fine, which always happens in those same spots too), if it was a cartridge issue you think it'd happen on the other TV, and if it were a console issue you think it wouldn't happen on both Mega Drives.

Thank you.

[chromium]

I've had a Mega CD 2 attached to a Mega Drive 2 for the last few years. I haven't really used the Mega CD 2, much, but had used the Mega Drive 2 fairly regularly. Today I went to use the Mega CD 2 for the first time in a couple of years and it's dead, looks like no power at all. I get no picture when I turn on the Mega Drive 2 without a cartridge while it's connected to the Mega Drive 2. The Mega Drive 2 works fine with a cartridge in while connected to the Mega CD 2.

I was hoping it was the fuse, which seems to be a common issue, but I tested continuity and it's fine

I guess I need to try the voltage regulator next. I was sure it would have been the fuse, seeing as it was working fine last time I used it and hasn't been moved or even detached from the Mega Drive 2 since then.

Also the power supply is fine as it works on my Mega Drive 1.

Edit: Scratch that, it lives! It suddenly started working after I cleaned the Mega CD 2 connector with alcohol and let it dry. The connector looked so cleaned I'm really surprised it was that.

[Chaos Fusion]

2 questions out of curiousity.
One thing that has always bugged me with Japanese Mega Drive cartridges is the sticker that covers the screws of the cart which I haven't found any place that sells replacement stickers. For reference in the future, are there any sellers or stores that sell official or replacement stickers for Japanese cartridges? It's mainly so I can check the authenticity of Japanese cartridges that I obtain.

Also, I just got a hold of a PAL copy of Blue Stinger and I learnt my region Free Jp Dreamcast either runs the game at 60hz in VGA which makes the cutscenes play too fast and composite video which displays the usual black and white flickering image. For a Japanese Dreamcast, would a official Scart RGB cable allow me to play the game in 50hz with colour or will it simply display at 60hz like VGA?

Edit: Actually, just learnt of the Toro box which looks like a nice piece off equipment. Anyone tested to see if it displays/runs PAL games correctly on NTSC hardware?

[ShadowFalls]

2 questions out of curiousity.
One thing that has always bugged me with Japanese Mega Drive cartridges is the sticker that covers the screws of the cart which I haven't found any place that sells replacement stickers. For reference in the future, are there any sellers or stores that sell official or replacement stickers for Japanese cartridges? It's mainly so I can check the authenticity of Japanese cartridges that I obtain.

I agree. They are quite hard to find. The best I could find was sellers on eBay who did custom order labels. Though once you take the back labels off it sadly won't be 100% original anymore.

[ShadowFalls]

I had an issue I was wondering if I could get assistance on.

I have a Sega CD Model 1 and the tray constantly ejects after closing it. One question I have with the laser which is a KSS-240a, does it have an anti-static point to desolder, if so where might it be? I could find information on Model 2 Sega CDs but not for Model 1s.

[infidelity]

As a test, with my Sega CD running, I would like to disable the RESET button on my Genesis, from resetting the Sega CD back to its title screen & ejecting the tray.

I've been looking at the expansion port diagrams online of the model 1 Genesis, to see which pin handles the RESET function, but I don't know abbreviations for that system, the only thing I see is DISK, so idk if that's where the connection is when you press the RESET button?

The point for all of this, is that I have a hard reset function via button combination with my 6 button controller, which takes me back to the Mega Everdrive menu, I can exit back from both Gen/32x, but not within the Sega CD. I want to be able to get back to my menu from within the Sega CD, but I need to disable the RESET function.*

If anyone knows which trace to sever, please let me know, thanks!

Edit - Or, is there a way to change the Sega CD, from checking if a cartridge is connected or not, to always present? Cause from the Everdrive I'm able to select any CD bios file to start the system, so I don't need the Sega CD looking to get permission.*

Please help! Thanks!

[infidelity]

Anyone?

[pyroesp]

As a test, with my Sega CD running, I would like to disable the RESET button on my Genesis, from resetting the Sega CD back to its title screen & ejecting the tray.

I've been looking at the expansion port diagrams online of the model 1 Genesis, to see which pin handles the RESET function, but I don't know abbreviations for that system, the only thing I see is DISK, so idk if that's where the connection is when you press the RESET button?

The point for all of this, is that I have a hard reset function via button combination with my 6 button controller, which takes me back to the Mega Everdrive menu, I can exit back from both Gen/32x, but not within the Sega CD. I want to be able to get back to my menu from within the Sega CD, but I need to disable the RESET function.*

If anyone knows which trace to sever, please let me know, thanks!

Edit - Or, is there a way to change the Sega CD, from checking if a cartridge is connected or not, to always present? Cause from the Everdrive I'm able to select any CD bios file to start the system, so I don't need the Sega CD looking to get permission.*

Please help! Thanks!

Looking at the schematics of the Sega CD, the /DISK signal is just tied to GND on the Sega CD side, probably to indicate to the Genesis that the Sega CD is plugged in, so that can't be the reset.
Maybe it's FRES on A25 ? It's coming from the 315-5309 chip, I/O chip ? (looking at this schematic : https://gamesx.com/wiki/lib/exe/fetc...stom_chips.png)
On the Genesis 2 schematics from the manuals I have found here, the FRES is coming from the custom chip IC6.

[pyroesp]

...

Also, I just got a hold of a PAL copy of Blue Stinger and I learnt my region Free Jp Dreamcast either runs the game at 60hz in VGA which makes the cutscenes play too fast and composite video which displays the usual black and white flickering image. For a Japanese Dreamcast, would a official Scart RGB cable allow me to play the game in 50hz with colour or will it simply display at 60hz like VGA?

Edit: Actually, just learnt of the Toro box which looks like a nice piece off equipment. Anyone tested to see if it displays/runs PAL games correctly on NTSC hardware?

I'm pretty sure the frequency will still be 60Hz. The cable doesn't change that. You probably need a 50/60Hz mod, if that is possible on a dreamcast.

[pyroesp]

Hey everyone - another random head scratcher for ya.

I picked up an "as is" 32x with no cords etc. I hooked it up and it plays genesis games but not 32x. (all cords/games tested and working on 2 other systems, OEM power etc)

Normally this is 99% the ribbon cables. Ive cleaned and re-seated them, but just get a black screen on the 32x games.

Everything else looks super clean and just like my other working 32x. (all the wires from the mother.daughter board go to the same spots, no blown caps etc)

Any idea what I could check next?

Thanks,

Measure voltage just to be sure it's getting power from the genesis.
You could swap the ribbon cables with the working 32x you have to see if there's a break in one of those, or just do a continuity test on them with a multimeter.

[pyroesp]

I have a Sega Saturn headscratcher, if anyone has any thoughts:

I purchased a model 1 MK80000 black/NTSC oval buttons a while ago, it worked perfectly but when opening it up I discovered that it was one of the revisions with the separate controller boards and that the ribbon cable was in rough shape. When trying to remove the ribbon cable, the pins actually came out of the ribbon cable port/connection.. The connector and cable were destroyed.

However, I was able to order in another ribbon cable and a PAL/JAP controller board which was completely different, so i desoldered the connector/port for the ribbon cable, and put it on my controller board. Amazingly, I didn't screw anything up and the controllers both work, as do the power and access lights.

When I hooked everything back up, the access light is constantly blinking red, and the CD spindle will not spin up, nor will the laser assembly move at all. (including the little lens going up and down a bit)

The board is able to tell when the CD lid is open or closed, the little cubes are both green on the system menu. I did reseat the other ribbon cable going from the CD board to the main motherboard and it doesn't look damaged.

If I leave that ribbon cable unhooked, the access light stops flashing which leads me to believe that the cable is somewhat working at least.

I'm thinking maybe the laser died, since it will not move into position or etc. Spindle could be dead as well, but I doubt it would start spinning until the laser did it's thing.

I will also note that when the lid it closed and a CD is in it, it will say "checking disc" after a while it just dissapears, no failure message. I've also tried cleaning the lens with Rubbing alcohol and a q-tip, as well as greasing the gears a bit.

Time for a new laser or? lol

Thanks everyone - have helped me out with alot of issues since I joined up!

You might not have soldered the connector correctly, or there's a difference between the PAL and the NTSC ribbon cable.
Try a continuity test from one end of the connector to the other. Check for shorts between pins too.
The CD drive might not be connected correctly and isn't receiving the command to read the disk, even though the screen says so.

You might want to check the schematics, if there are any available, just to see if shorting pins or incorrectly connecting pins might damage the cd drive.

EDIT:
You might want to check if the CD drive has power too.

[pyroesp]

Seeing as I need 50 posts before I can make my own thread, I'll just ask here.

I've recently repaired a Sega Mega-CD 2, that originally didn't want to boot. The thing was covered in flux, just gross.

I burned Sonic CD to a CD-R, just to test the system.

When playing Sonic CD, I wait on the start menu so the intro movie can start playing.
This intro doesn’t load all the time, and when that happens the CD drive makes noises like it’s trying to read or find the correct spot on the CD (?) but then just stops spinning the disk.

I can get it to load by opening and closing the port of the CD drive. That resets/homes the laser head and then the CD drive starts spinning and reading the disk again.

I’ve tried another game and this one doesn’t want to load the levels unless I open and close the CD port.

Anyone knows why this happens and/or knows how to fix this ?

I've written about this repair on my github page for those who want to have a laugh at my stupidity :
Part 1: https://pyroesp.github.io/electronic...mega-cd-2.html
Part 2: https://pyroesp.github.io/electronic...-2-part-2.html

[lumclaw]

I'm pretty sure the frequency will still be 60Hz. The cable doesn't change that. You probably need a 50/60Hz mod, if that is possible on a dreamcast.

I think VGA automatically uses 60hz, skipping the 50/60hz prompt if a game has it.
Most likely the NTSC dreamcast composite/s-video encoder doesn't support PAL, and will display messed up colors in 50hz. (other consoles like gamecube have similar issues)

But consider this speculation. I don't own PAL dreamcast games.