Sega SC-3000 Repair
Sega SC-3000 Repair
Defect:
- The graphics of the games is not displayed correctly.
- The BASIC cartridge does not work.
Replaced Components:
- 2 x MCM4517-15 RAM (IC12/IC13).
Note:
I have replaced the two RAM MCM4517-15 with a classic RAM 4164 (also used in the Commodore 64) paying attention to short-circuit the pin 9 and 10 of the 4164 RAM.
The MCM4517-15 RAM are 16,384 Words x 1 bit while the 4164 is 65,536 x 1 bit, both are PINOUT compatible except for the pin 9 which in the MCM4517-15 is not used while in 4164 is A7.
This “tricks” to short-circuit the pin 9 and 10 instead of using a resistor of pull-down is also used in some coin-op arcade boards that use the same RAM.
Gallery of the repair:
Categories: Projects / Repairs, Today, Various
congratulation, good work!!!