171-6395A Board Info

Introduced in late 1992, the 171-6395A is the final board revision for PAL Sega Master System II consoles. It is largely identical to the 171-5922A it replaces, but has a 32-pin 2 megabit (256 kilobyte) BIOS ROM with a slightly truncated version^[1] of Sonic the Hedgehog as the built-in game instead of Alex Kidd in Miracle World. Sega also changed the video encoder from the through-hole Sony CXA1145 to the surface-mount Fujitsu MB3514, which is a largely pin-compatible clone of the CXA1145. This is the only Master System variant outside of Brazil to use this particular video encoder. Aside from these changes and the addition of several capacitors, most of the component footprints and designations are also the same as the 171-5922A. Production continued until some time in 1993, though Sega assembled consoles using this board until 1995, a year before Sega officially discontinued the Master System in PAL regions.

All boards have the silkscreened text SEGA IC BD M4Jr. PAL 2M at the lower left corner. Sega did not silkscreen the assembled part number (beginning with "837-"). Most boards have white silkscreened text and a matte finish solder mask, while some have yellow text with smooth solder mask.^[2]

Parts List

All resistors are 1/6 W.

References