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

[kool kitty89]

I recently got a CD Model 1 with an early HD Model 1 genesis. When I got it it would power on (but only the "Ready" light, and no bios) and the drive wouldn't open.
Opening it up I found that there was a copy of Lethal Enforcers in the drive (which I then removed by unscrewing the plastic plate with magnetic thing that holds the disc to the drive spindle) and the 25-pin ribbon cable from the main board to the CD drive was disconnected (from the drives end) with the ceramic ring loose in the case. SO I put the ring back on, pluged the cable back in and re-assembled the unit.

Setting it up again and turning it on, the "access" light came on blinking and the bios booted fine, reset opened the tray and I tested that a few times with no problems. I thin inserted the Lethal Enforcers disc (which is my only CD game for now) and the game loaded and seems to work fine. However when I hit reset again to eject it nothing happened and only the "ready" light was coming on again.

So I took it apart again and didn't notice anything wrong, so I removed the CD again and put the cover back on and tried again. Again it seemed to work, but I ran into the same problem whan trying to eject. (no eject, and subesequently no boot)

I then tried removing the disc once again, and now it doesn't seem to be booting or opening the tray reliably (even with no disc). That main ribbon cable that came disconnected looks like it may have some damage. (the first wire -closest to the front of the unit- looks pinches at one point) I tried flipping the cable (so the pinched part was on the opposite end) and re-connecting it this way and found I couldn't get it do work at all other than the "ready" light coming on. (so I put it back to normal and it's still flaky as before)


Edit: I should note the previous owner was a smoker (obvious by the smell) and I cleaned a fair amount of build-up off the expansion port's pins. (the board portion, the slot seems failry clean with little coming off when cleaned, same for the cartridge port)

Opening up the Genesis I found it pretty much standard early model 1, except for a small resistor soldered between pin 6 and 16.


Messing around with the CD some more, it seems to work for a little while after being powerd off for a while. (something like 5 minutes, though it varies) But as soon as I hit reset for a second time (after ejecting the tray and pushing it lightly to insert it) it starts just lighting up the green "ready" light and not booting the bios or ejecting the tray.
Though I can eject it several times without much trouble, though that eventually leads to the same problem too; when hitting reset with the tray out the tray closes and then opens again, sometimes pausing or slowing down while retracting, sometimes it will even stick unless reset is being held down)

[journey]

Hi to all,

Recently I have bought a Victor Wondermega RG-M1, and
I have a problem with it.
The sound is "STRANGE"...
It seems that the channels have a different audio level, for example, the drums are very "padded","hollow", and some channels have low volume, and others high volume..
I am sure of this because I have another Megadrive and the sound of this is absolutely normal.
The problem is present also through the headphone jack, this means that is not a problem of the RCA audio.
I think that the real problem is the mixer audio of the wondermega.
My question is:
is it possible to bypass the mixer audio? or disable it?

any suggestion?

Thanx for your help!

Gianluca

[TmEE]

Wondermega has PSG much more louder than it should, and you can hear it so on any output there is. I have not done too much research on the Wondermega, but I can say that fix for it would be rather simple... it will most likely involve only replacement of one or two resistors.

[journey]

hi!
thanx for reply
The problem isn't only the PSG, but also the FM sound is "strange" but so strange that in some games, the melody of the music is almost unrecognizable.
like you said, perhaps i have to replace some resistors, but wich exactely? I've tried to open the wondermega, but there are too many resistors...and i don't know to do :-/

[TmEE]

There is of course some filtering and distortion issues with FM, but those should not cause any extreme sound issues...

I have not got that far to figure out a fix for the system... it is some of the most evil machines there are... tightly packed and full of complex analog circuits....

[vegeta8259]

I've seen many Genesis 3's w/ region mods out there, but I can't seem to find a tutorial on how to do it... Anybody know of a good guide?

[old man]

I've seen many Genesis 3's w/ region mods out there, but I can't seem to find a tutorial on how to do it... Anybody know of a good guide?

http://www.gamesx.com/importmod/gen2import.htm

[TmEE]

Hope you have such kind of Genny3... I know there's units with the region jumpers unmarked

[Iced Snowman]

I always wondered why MK II has less cartridge connectors on the label side of the cart. Can anyone explain why this is? Also, are there other carts out there with similar designs?

[TmEE]

There's a lot of signals on the cartslot that are not needed by a cart, and some carts have no contact on the board where those signals are. I've seen this done on some EA cart... it does not matter if there's a contact thats unused or no contact at all.

[Iced Snowman]

So does that mean that the majority of games have unused contacts on their cartslots?

[TmEE]

yes, only game using most of the signals on cartslot is Virtua Racing, and 32X uses all aswell.... the extra signals can be thought of as the outer signals on SNES cartslot that carts with extra stuff in them use.

[kool kitty89]

Didn't many of the older systems only use one side of the pins? I know the 2600 did (there's only a 12-pin ribbon cable attached to the 24-pin slot, which limited addressible memory to 4 kB, even though the 6507 supported 8 kB w/out bank switching)
I believe the NES/Famicom did this as well, but I'm not sure. (60/72 pins seems a bit excessive otherwise, and only 16 should be used for addressing)

On the Genesis I think it's mostly the 3rd party carts that are missing pins, the only NES game (or from any system other than Genesis) that I've seen this is "Phantom Fighter" which is missing 11 pins toward the middle.

[SuperMonacoGP]

Can anyone help me with my Mega Drive... I bought it off e-bay about 3 weeks ago, played it quite a lot since I bought it, it came in excellent condition, in original box etc... Played perfectly, then I disconnected the wires and put it back in the box for about a week, connected it back up today and tried to play it and it's not working now

We tried it on the T.V I usually play it on and the black screen comes up but that is it, no start screen or anything. So I tried it on another T.V and the music came on when we tried it on that T.V but there was no picture on it, just the black screen again. So tried it on another T.V and the same happened again... Black screen, but sound.

Any idea what could have happened? I've cleaned all the carts and inside the Mega Drive but can't get any picture up now, only the sound. I don't know how it could have broke though as I hadn't mistreated it or dropped it

[Knuckle Duster]

Can anyone help me with my Mega Drive... I bought it off e-bay about 3 weeks ago, played it quite a lot since I bought it, it came in excellent condition, in original box etc... Played perfectly, then I disconnected the wires and put it back in the box for about a week, connected it back up today and tried to play it and it's not working now

We tried it on the T.V I usually play it on and the black screen comes up but that is it, no start screen or anything. So I tried it on another T.V and the music came on when we tried it on that T.V but there was no picture on it, just the black screen again. So tried it on another T.V and the same happened again... Black screen, but sound.

Any idea what could have happened? I've cleaned all the carts and inside the Mega Drive but can't get any picture up now, only the sound. I don't know how it could have broke though as I hadn't mistreated it or dropped it

Take the first logical step. You disconnected wires.
Inspect the cable,and socket. See if any pins are broken off, missing, etc.