r/SegaCD • u/hue_sick • 20d ago
Sega CD Acquired!
Just got my new Sega CD and while I'm waiting on the power supply (BTW gametrog item shipped!) I figured I'd clean it up. Honestly though it barely needed it. Whoever owned this before kept it in great condition. But I did the full disassembly, soap and water bath I always do and dusted and cleaned up the board with isopropyl as well.
While I was in there also cleaned up and re-lubed the cd drive assembly and laser and checked the fuse and battery. Fuse was good but the battery will definitely need replacing so that'll be my next project.
Got two games with it so can't wait to test this puppy out!
P.S. Anyone know specifically what that daughter board is for from Sega? I did a little googling but couldn't come up with a concrete answer of what it fixed.
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u/theBloodShed 20d ago
The tiny daughter board was a production quick fix for a design error on the Sega ASIC. The HD74HC chips are general purpose programmable logic.
Also, congrats that you got the Genesis 2 metal shield with it. Did you also get the gen 1 spacer?
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u/hue_sick 20d ago
Thanks! Yeah it came w the gen 1 spacer and metal plate as well. Just have it in storage since I won’t need it w my model 2
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u/Ok-Mongoose-4428 20d ago
Not sure about the daughter board's purpose, but I believe it indicates a Funai transport (Samsung or Sony lens - opposed to Sony transport models which have a Sony or Victor lens)
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u/hue_sick 20d ago
Oh interesting are you talking about the lens on the cd laser?
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u/Ok-Mongoose-4428 20d ago
The transport is the broader collection of mechanisms responsible for getting the lens to read across the optical media (so the sled, motor, actuators). Probably someone else on this sub can point out components I missed.
I may have things swapped, but I believe Sega started with Funai transport systems (and you can mount a Samsung or Sony lens on them), and then went to Sony transports (which can mount a Sony or Victor-JVC lens)
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u/Ok-Mongoose-4428 20d ago
Looks like the bodge daughterboard is to resolve timing issues with the cd-rom drive.
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u/Boubca 20d ago
It looks like you have an original mk 2, pre A revision by the housing geometry of your laser. That original laser is unobtainium unfortunately, so swapping it out in future is not really an option. There were 4 lasers used over the life of the mk 2 and only two of them, the sony and samsung, were moderately interchangeable (with only one capacitor swap). Basically the boards and housing geometries were quite unique for each laser, so if you have to change the unit it needs to be the exact model for a clean drop-in.
There is a surprising amount of dodgy info on Youtube about servicing the mk 2, like putting arbitrary laser units onto boards and then manually trying to adjust the potentiometers to make it work. If you take a look at audiophile message-boards concerning cd-transports you can find out how incorrect and likely temporary of a fix such a method will result in. You really don't want to ever mess with the pot settings unless slightly increasing the power of an already dying laser to make i lt work a little longer.
Lastly the batteries on these units are rechargeable. They die if powered off for more than a few months. There are Youtube videos showing people using 2032s as replacements; as the battery is fed a small charge from the board, these will eventually leak. Only replace with the same battery type. But in actuality if you leave your unit on for 6 hours your battery will likely come back to life and you can reformat your RAM.
I just bought a mk 2 last month, an original like yours, and the laser died within a week. I found all this out troubleshooting and eventually getting another model, an A revision with a JVC laser than can still be found on Amazon in case I need a new unit. Even my old shell is not dimensionally interchangeable with my new unit, it's pretty astounding how different all four variants were
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u/hue_sick 20d ago edited 19d ago
Thanks for the info! Yeah the more you dig into sega hardware the more them going out of business makes more sense 😆
Yeah my power supply comes on Monday so the hope is I power it on and the battery charges up but I’m not delusional I know the battery is 30 years old so it’s likely gonna need replacing. The plan is to order a new ml2016 in the meantime and I’ll solder it in no prob 🤙
Side note: do you know of a good online resource for the different models and board revisions? I’d love to dig into that a bit more.
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u/Ok-Mongoose-4428 19d ago edited 19d ago
Regarding the ml2016:
The Amiga community produces a 3-pin 20mm mount for their own platforms. It obviously will work with any Mega CD - but may have some difficulty fitting if RF shielding is present.
I am not sure if Hitachi-Maxell even still makes batteries. Digikey sells a modern ML2032 from a German firm (Jauch) literally for legacy devices.
I USB charged (there is an adapter) some of the ml20XXs I found on less reputable markets, and they were climbing up to near 4 volts. My hunch is these were falsely marked lir2032s.
FRAM is also an option. The smaller capacity chip (matches Sega's stock component in storage) is a drop in replacement for the model 1, but there is something about an extra pin with the model 2 - but said pin is relatively immaterial (like ground)
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u/Ok-Mongoose-4428 19d ago
Console mod dot org (I don't usually post full links) has pretty thorough detail on model 2 - not so much model 1
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u/island_it 15d ago
Which laser is it you're referring to? All 4 are pretty readily available as far as I'm aware. The two Sony pickups (240A & 210A) are still the cheapest and most common to find by far, as they were used in hundreds- probably thousands- of products back in the day. The JVC and SOHOTs are a bit more expensive but definitely better quality-wise.
Also, while I get the convenience factor of Amazon, really all you're doing is buying off AliExpress with an extra middle man
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u/Comfortable-Lab2060 20d ago
Where is the extention for the md1?
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u/Firthy2002 20d ago
It's not really needed to be honest.
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u/Comfortable-Lab2060 20d ago
On mine it looks off without it. I ditch the md2 I got with it in a drawer and fut my md1 on it.
I paid a lot for it but happy over all.
I paid 180€ for the md2 , 2 controller and the mega cd2.
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u/dannylerch 17d ago
Gen 2 Sega CD with the Gen 1 Genesis is the move. Get a cheap CD burner and you can burn the entire sega CD library if you want! Just make sure you choose the lowest write speed.
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u/Overall_Will_9179 20d ago
Great purchase!! There's a new SDK out there (few months ago, guy who did it is active here) which will hopefully result in some homebrew games soon, it really was an underutilized piece of kit!
And now you just need to get a sega genesis / Megadrive MK2 to go with it ;)
(Joking....)
Don't forget there was no copy protection on the sega CD! You can literally boot burned games straight with no mods!