SEGA PART #171-5507D

2 Megabit PCB's - Date 1987

These are all 2 Megabit games tied to this PCB.  It seems that the Master System has combination ROMs and PCBs that go together depending on the size of your game.  These ROMs have 32 PINs, and the serial number is found on the back of the PCB on the left-hand side.

Games like Double Dragon have also been found using the 171-5507 PCB, yet the ROM MPR numbers remain the same.  The only difference between these 2 PCB's is the following:

Both the 171-5507 and 171-5507D appear to be identical with the exception of missing pins.  If the game dosen't use the pins, it would be cheaper to manufacture with them removed.  Pins 3, 4, 5, 11, 34, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49 & 50 have been removed from the PCB.