Dreamcast PCBs and Schematics

[RDC]

I haven't messed with any of this stuff in ages, and hopefully it'll do someone that is looking for this kind of thing some good. Don't take any of it for granted, as there very well could be some errors here or there, and if any are found please do point them out and hopefully one day I can eventually get around to correcting them here.


VA0 TOP - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/IC%20BD%20KATANA%20MAIN%20VA0%20TOP%20NO%20CONNS.jpg

VA0 BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/IC%20BD%20KATANA%20MAIN%20VA0%20BOTTOM.jpg

VA0 TOP CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/IC%20BD%20KATANA%20MAIN%20VA0%20TOP%20CLEAN.jpg

VA0 BOTTOM CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/IC%20BD%20KATANA%20MAIN%20VA0%20BOTTOM%20CLEAN.jpg

VA0 SCHEMATIC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/Dreamcast%20VA0%20FULL.pdf


VA1 TOP CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/IC%20BD%20KATANA%20MAIN%20VA1%20TOP%20CLEAN.jpg

VA1 BOTTOM CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/IC%20BD%20KATANA%20MAIN%20VA1%20BOTTOM%20CLEAN.jpg

VA1 SUB BOARD BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/KATANA%20SUB%20BD%202%20BOTTOM.jpg

VA1 SCHEMATIC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/Dreamcast%20VA1%20FULL.pdf


VA2.1 TOP - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA2.1/IC%20BD%20Katana%20Main%20VA2.1%20Top.jpg

VA2.1 BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA2.1/IC%20BD%20Katana%20Main%20VA2.1%20Bottom.jpg

VA2.1 TOP CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA2.1/IC%20BD%20KATANA%20MAIN%20VA2.1%20TOP%20CLEAN.jpg

VA2.1 BOTTOM CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA2.1/IC%20BD%20KATANA%20MAIN%20VA2.1%20BOTTOM%20CLEAN.jpg

VA2.1 SUB BOARD BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA2.1/KATANA%20SUB%20VA2%20BOTTOM.jpg


GD-ROM BOARDS

XU937 TOP - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/XU937/XU937%20TOP.jpg

XU937 BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/XU937/XU937%20BOTTOM.jpg

XU937 TOP NO IC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/XU937/XU937%20TOP%20NO_IC.jpg

XU937 BOTTOM NO IC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/XU937/XU937%20BOTTOM%20NO_IC.jpg

XU937 SCHEMATIC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA0/XU937/Dreamcast%20GD-ROM%20XU937.pdf


XV779 TOP CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/XV779/XV779%20TOP%20CLEAN.jpg

XV779 BOTTOM CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/XV779/XV779%20BOTTOM%20CLEAN.jpg

XV779 SCHEMATIC - https://www.acidmods.com/RDC/SEGA/Dreamcast/VA1/XV779/Dreamcast%20GD-ROM%20XV779.pdf


CONTROLLER

HKT-7700 TOP - https://www.acidmods.com/RDC/SEGA/Dreamcast/HKT-7700/HKT-7700%20Top.jpg

HKT-7700 BOTTOM - https://www.acidmods.com/RDC/SEGA/Dreamcast/HKT-7700/HKT-7700%20Bottom.jpg

HKT-7700 TOP CLEAN - https://www.acidmods.com/RDC/SEGA/Dreamcast/HKT-7700/HKT-7700%20Top%20CLEAN.jpg

HKT-7700 SCHEMATIC - https://www.acidmods.com/RDC/SEGA/Dreamcast/HKT-7700/HKT-7700.pdf

[ShadowGuy]

Any chance you have scans of the PCB where the controller ports are?

[RDC]

That's honestly one board, technically 3, that I never did mess with getting scans of. The KATANA SUB BD 01 (VA0) and the KATANA SUB BD 2 (VA1) are both single sided PCBs and there isn't really much going on there. Even the SUB BD VA2 (VA2.1) is pretty much single sided, even though it has a top layer but that's just all ground.

The VA0 and the VA1 schematics have the SUB BD 01 and SUB BD 2 traced out in there, it's the little circuit kind of all by itself almost right in the middle of the whole mess, CN1 is the ribbon cable connector, on there and CN1A/CN2A are the controller port connectors.

The SUB BD 2 and the SUB BD VA2 are technically the same and interchangeable, but that SUB BD 01 that is used in the VA0 can only be used on it, without modifying things.


EDIT: Added the VA1 and VA2.1 Sub board PCB scans, bottom side only for now, but there isn't anything going on top side trace wise really.

[ShadowGuy]

Thank you for the uploads.

[LSL]

I haven't messed with any of this stuff in ages, and hopefully it'll do someone that is looking for this kind of thing some good. Don't take any of it for granted, as there very well could be some errors here or there, and if any are found please do point them out and hopefully one day I can eventually get around to correcting them here.

....

Thanks again to RDC (helped me with DualShock components 4 years ago)! These scans and schematics helped me fix my VA1 and VA2.1. I bought both Dreamcasts (with problems) at least 10 years ago, the VA1 came without GD-ROM and in 2020 I bought a 3.3v GD-ROM on AliExpress.

In September I imported another Dreamcast, it came from Japan. I didn't know which revision and when it arrived I saw that it was a VA0. He had a problem with the GD-ROM card that was resolved. This board is different from the XU937 and XV779, but has similarities with the XV779. It has no name and I called it 171-8129A because that sequence is on the board.

The GD-ROM that I bought on AliExpress in 2020 came with this same board (171-8129A). The curiosity is that the VA0 GD-ROM board works with a 5v signal and the VA1 GD-ROM board works with a 3.3v signal on the same board model. Will IC5 be different with the same label (313-5691)? Or is it that even though it is described as a 3.3v, it will work on VA0 with a 5v signal?

Finally, I leave my small contribution to the topic, front and back photos of board 171-8129A.