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View topic - Replacement edge connector for SC-3000 cart slot

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  • Joined: 03 Oct 2011
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  • Location: New Zealand
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Replacement edge connector for SC-3000 cart slot
Post Posted: Fri Feb 22, 2013 8:41 pm
Hi All

I've found a suitable replacement edge connector for the Sega SC-3000.

Sullins EEA22DTBN
www.sullinscorp.com

EEA22DTBN (PBT / Tin plated contacts, 22 pins, dual sided, 0.180" tail
length, no mounting ears, 0.610" body height, 0.370" body depth, 0.150"
row spacing, right angle mounting).

I put a bit of super glue underneath the edge connector before soldering it in to help take some of the strain when inserting / removing carts. The original connector had some sort of adhesive there too which I had to lever up with a screwdriver when removing the original connector.

Note - I've only done mechanical fit tests and basic continuity tests to the pins at the back of the cart as this SC-3000 mainboard is dead. The fit is a bit tight on the carts, but I assume that will loosen up with use.

The EEA22DTAN could be a slightly better alternative. That only has 0.100" tails instead of 0.180" tails, as the 0.180" pins poke a fair way through the mainboard.

Note also that the row spacing on the SC-3000 is 0.125", not 0.150". But the pins bend into place so easily you might not even notice the bend if you didn't know the spacing was out.

The insertion depth of the cart PCBs into the slots is a little shallower than I would like, but it still seems to get an acceptable grab on the cart contacts.

I'd just like to say a huge thank you to Lucinda over at Sullins Connector Solutions who helped me narrow down the choice of connector.

Cheers
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_01.jpg (76.75 KB)
Sullins EEA22DTBN Edge Connector
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_01.jpg
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_02.jpg (114.48 KB)
Replacement edge connector on SC-3000 motherboard
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_02.jpg
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_04.jpg (119.5 KB)
Replacement edge connector on SC-3000 motherboard
Sullins_EEA22DTBN_Sega_SC3000_Edge_Connector_04.jpg
Sullins_Edge_Connector.rar (537.8 KB)
Sullins EEA22DTBN Edge Connector Datasheet

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Post Posted: Fri Feb 22, 2013 9:29 pm
Another alternative;

http://www.tototek.com/store/index.php?main_page=product_info&cPath=22&p...
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Post Posted: Sat Feb 23, 2013 12:06 am
Thanks. I think that tototek part is a vertical connector with straight mounting pins. You need a right angle connector with a 90 degree bend in the mounting pins for the sc-3000.
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Post Posted: Sat Feb 23, 2013 8:56 am
Ah yes, the Tototek one would require a lot more work. Good find.
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Post Posted: Sat Feb 23, 2013 8:07 pm
You know, I suppose it might be feasible to use a straight through connector and bend all the pins into position yourself if the mounting pins were long enough (probably around 2cm to 2.5cm long). So a bit of a pain, but that could be a backup option. Good thinking. I hadn't considered that before.
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Post Posted: Wed Mar 06, 2013 9:43 pm
Quote
Note - I've only done mechanical fit tests and basic continuity tests to the pins at the back of the cart as this SC-3000 mainboard is dead. The fit is a bit tight on the carts, but I assume that will loosen up with use.


This SC-3000 is working great now, and I can confirm that the replacement edge connector is working well with multiple different carts. Description of the fix follows below.

When I plugged it in, I got some sort of video signal. But instead of the normal black screen and 'medium tone' that you get with a SC-3000 with bad cart insert, I was getting a blue screen and slightly different tone. No music from games carts. I check the voltage to the VRAM ICs - something around 3v.

The 5v regulator was stuffed - it was only putting out around 3 volts. Once I replaced that, some of the carts would sort of work, but they had memory errors. I isolated that by testing with the multicart. It worked perfectly with the multicart which has its own 32KB of SRAM on board, but you can also disable that with jumpers on the multicart and force it to use the SC-3000s on-board 2KB SRAM. As soon as you used the SC-3000s 2KB SRAM the weird problems with games and the cart menu system started again. You can perform similar isolation testing with a BasicIIIB cart. A Basic IIIA cart gives a memory error (2 beeps repeated) in this situation because a Basic IIIA cart actually uses 18KB of RAM - 16KB on the cart from $8000 to $bfff then the 2KB of SRAM on the SC-3000 from $c000 to $c7ff.

I sourced some NEC D4016C chips which were the cheapest pin compatible replacement I could find for the original MB8128. I removed the original chip last night with solder wick then socketed and replaced with a D4016C. Works great now.

I got that motherboard in a garage sale back in about 1999, and it was dead when I got it. So I'm quite happy to get it up and running again :)


segaSC3000_replacedSRAM.jpg (190.1 KB)
Attachment fairy
segaSC3000_replacedSRAM.jpg

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Post Posted: Tue Feb 23, 2021 4:25 am
Hi All

Just an update on this antique thread. Someone I know bent the edge connector pins recently on his Sega SC-3000.

It looks like you may not be able to get the tin plated part I mentioned above any more, but Sullins still appear to have the gold plated versions, and if you're lucky they will send you a sample.

EBA22DTBN
EBA22DTAN

Hopefully his repair is successful :)

Cheers
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