Hi Guys !
I have a Dreamcast with blown video DAC and would like to repair it. The schematics say that the DAC is IC401 (BU1426KS) but strangely no datasheet could be found. The closest one was BU1424K, BU1425AK and BU1425AKV. Would it be possible to use any of these chips as replacement for the original DAC ?
Dreamcast motherboard
http://upload.wikimedia.org/wikipedia/commons/9/9c/Sega-Dreamcast-Motherboard.jpg (http://upload.wikimedia.org/wikipedia/commons/9/9c/Sega-Dreamcast-Motherboard.jpg)
Video DAC schematics
http://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:dreamcast_video_dac.pdf (http://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:dreamcast_video_dac.pdf)
BU1424K, BU1425AK and BU1425AKV datasheets. Please see the attachment.
Keep the scene alive !
Eidis
I don't want to be the barer of bad news eidis.. But after searching high and low around the interwebnets, I could not find any data sheet on the IC used for the Dreamcast's video DAC or any more additional info on it.. it seams to me like it's a customized and made to order part made for Sega.
You could play Doctor Eidis and take a replacement one from an already dead Dreamcast's motherboard as a doner... OR play Victor Frankenstein and keep trying similar parts from the same manufacture until you find one that works.
It would also seam that the Dreamcast has a similar problem to the X68k, with certain monitors killing ICs or the DAC in the video output circuit. but with the Dreamcast, Static shock, poorly made AV leads and certain kinds of TV/Monitors are the major culprits for killing the video DAC in the Dreamcast.