Sega SC-3000H not loading carts

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Sega SC-3000H not loading carts

Postby Otaku on Thu Jul 31, 2014 1:19 pm

Hi all

Names Harley and I'm mainly a retro video game console collector but just recently got into computer video game consoles and picked up a Sega SG-3000H which currently doesn't work at the moment :(

It powers on and displays a black screen with a humming sound which I think is normal when there is no cart inserted into the system, but it also does this when I do insert a cart. I have tried multiply carts and still the same thing, I have also cleaned the carts and the connectors on the system with some electrical clean and lube spray and still having no luck.

If anyone has any information on how I can get this system working it will be much appreciated.

Thanks
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Re: Sega SC-3000H not loading carts

Postby Audronic on Thu Jul 31, 2014 4:16 pm

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Re: Sega SC-3000H not loading carts

Postby mrad01 on Thu Jul 31, 2014 6:50 pm

You need to clean the card edge slot betterer. I had *exactly* the same issue and thought I had cleaned it perfectly. Wrong.

Get some cardboard and cut it (and maybe fold it) so it press fits into the slot. Work it in and out. You will see blank marks on the card. Re cut and keep doing this until there are little to no black marks on the card.

That'll fix it. I have 2x SC3000s which I got working using this method - and the symptoms were the same as you describe.

Marcus
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Re: Sega SC-3000H not loading carts

Postby Otaku on Thu Jul 31, 2014 8:04 pm

Thanks, will clean it up some more and see if that works
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Re: Sega SC-3000H not loading carts

Postby Carcenomy on Fri Aug 01, 2014 5:51 pm

Yep, the slot in the 3000 is a finicky temperamental jackass of a thing, and a really good clean usually puts it right.
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Re: Sega SC-3000H not loading carts

Postby Otaku on Sat Aug 02, 2014 2:36 pm

Ok gave it a really good clean there are no more black marks but i'm still having the same problem :(

Is there anything else that could stop the carts from loading?
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Re: Sega SC-3000H not loading carts

Postby mrad01 on Sat Aug 02, 2014 3:12 pm

Keep cleaning....

Seems nuts, but, keep cleaning...

(Obviously make sure the cart edges are clean too.)
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Re: Sega SC-3000H not loading carts

Postby honestbob on Sun Aug 17, 2014 7:37 am

Hi Harley

The other guys are right. You can usually fix that by carefully cleaning the cartridge slot and sometimes the connector edge on the actual cartridge itself. Also do a visual inspection looking for bent or damaged pins on the edge connector.

The noise is because the SC-3000 doesn't have a BIOS or ROM on-board. It can only execute code that it sees at the cartridge slot. By default, when you turn the SC-3000 the sound chip emits that 'humming sound', and the SC-3000 has to execute code from the cartridge to turn it off.

If cleaning the cart edge doesn't work and you are confident working inside the computer, then this is how you open it:

http://www.sc-3000.com/index.php/How-to ... board.html

And here is a schematic. This was scanned by natshaw, and I think the original came from radar, both from the classic computer forums.

http://www.sc3000-multicart.com/images/ ... tic_A3.jpg

If you do open it up, the problem is still likely to be somewhere around that cartridge edge connector because the fact that you are getting that black screen and humming noise suggests the unit has power and the video RF circuitry is working. Check the solder on the underside of the edge connector. If the glue under it has come loose then some of the joints might have cracked.

Aside from that, I haven't seen any CPU failures on SC-3000s. I have seen VRAM chips and SRAM chips that needed replacing. And natshaw managed to fry the VDP one time :) You can replace all those if necessary, but focus on the cartridge edge connector system first.

Also check the voltage levels coming off the voltage regulator is 5v as I have seen one of those go bad before too.

Good luck :)
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Re: Sega SC-3000H not loading carts

Postby Otaku on Sun Aug 17, 2014 8:04 pm

Thanks for the extra information.

But still can't get it to work! Cleaned it continuously and still had no luck, so opened it up an re-solded all the pins on the connector and still nothing.
I think I will have to replace the cartridge edge connector if I can find one...
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Re: Sega SC-3000H not loading carts

Postby mrad01 on Sun Aug 17, 2014 8:51 pm

Otaku wrote:Thanks for the extra information.

But still can't get it to work! Cleaned it continuously and still had no luck, so opened it up an re-solded all the pins on the connector and still nothing.
I think I will have to replace the cartridge edge connector if I can find one...


Use a meter to check the edge connector contacts get through to the motherboard solder points. How many carts do you have? Do you know if any work?

Mine was extremely frustrating to get working - it was all about the edge connector and carts
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Re: Sega SC-3000H not loading carts

Postby honestbob on Mon Aug 18, 2014 9:08 am

mrad01 wrote:Use a meter to check the edge connector contacts get through to the motherboard solder points. How many carts do you have? Do you know if any work?


I agree. First off use multi-meter to check for continuity. If the springs appear to be making good contact with the cartridge edge and if you get continuity from the edge connector through to the motherboard solder points then it probably isn't the connector itself.

I have seen some of the traces lift on the motherboard PCB before, so you might also want to follow the PCB traces with your eye and check for continuity. In fact, I would use a multi-meter to check continuity once you have eyeballed the trace path. If you find a broken trace you can fix it with a jumper wire or similar.

And good point about using a known working cart. Start off with games cartridges rather than Basic cartridge as those are more complicated internally and can fail (they have DRAM inside them). It is unusual for a games cart to totally die as they are pretty simple inside. But if they were stored in a damp environment then there could have been some corrosion.

Otaku wrote:I think I will have to replace the cartridge edge connector if I can find one...


They are hard to get unfortunately. Not impossible, but hard. Lemme see if I can find the old threads where I published a working part number...

Ah - here you go

viewtopic.php?f=11&t=958

That replacement edge connector is still working fine. Your best bet is to ask Sullins to send you some sample ones, because otherwise you have to buy a minimum of 10 at about $8USD each or similar from memory.

But do the continuity checks with a multimeter first. And check the voltage levels on that 5v regulator.
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Re: Sega SC-3000H not loading carts

Postby Otaku on Mon Aug 18, 2014 3:03 pm

Will get the multi-meter out and start testing

Can't be the games as I have tested them on a Sega Mark III and they work fine

Thanks for all the information everyone :D
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