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Sega SC-3000 Repair

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:

  1. grendyzer
    November 28th, 2018 at 00:27 | #1

    congratulation, good work!!!

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