This is the initial board revision for the Sega Master System in NTSC regions, and was produced from late 1986 to late 1987. It is denoted by its use of the Sony V7040 video encoder, a vertically oriented Z80 CPU, and metal leaf switches for the Pause and Reset buttons. This is also the only NTSC Master System board revision to have fully plated through-holes, making it significantly more durable than later revisions. In France, Sega opted to use this board revision for Master System consoles sold there as it could be easily adapted to provide only RGB output without the extra expense incurred from the additional clock divider circuitry in its PAL equivalent (board part number 171-5385). Sega discontinued the 171-5379 by the end of 1987 and replaced it with the cost-reduced 171-5532 (assembled part number 837-6405).
Several silkscreen variants exist which have the following listed:
- 837-6067 SEGA M4 POWERBASE/NTSC
- 171-5379 MSPOWER BASE/NTSC
- SEGA 1986 MS POWER BASE/NTSC (mainly found in French consoles)
- 171-5379 SEGA 1986 MS POWER BASE/NTSC (also found in French consoles)
Parts List
All resistors are 1/8 W.
| Designation | Value/Name (NTSC) | Value/Name (France) | Notes |
|---|---|---|---|
| C1 | 10 uF 16V | ||
| C2 | 0.1 uF | ||
| C3 | 0.1 uF | ||
| C4 | 100 uF 10V | ||
| C12 | 0.1 uF | NP | |
| C13 | 0.1 uF | NP | |
| C14 | 0.1 uF | NP | |
| C17 | 100 pF | NP | |
| C18 | 0.01 uF | NP | |
| C20 | 100 uF 10V | NP | |
| C21 | 0.1 uF | NP | |
| C22 | 100 uF 10V | NP | |
| C23 | 0.1 uF | NP | |
| C25 | 100 uF 10V | NP | |
| C28 | 100 uF 10V | NP | |
| C29 | 0.1 uF | NP | |
| C32 | 47 pF | NP | |
| C33 | 100 pF | NP | |
| C37 | 100 pF | NP | |
| C39 | 100 pF | NP | |
| C41 | 0.01 uF | NP | |
| C49 | 10 uF 16V | ||
| C104 | 0.1 uF | ||
| C105 | 0.1 uF | ||
| C108 | 33 pF | ||
| C109 | 33 pF | ||
| C110 | 0.1 uF | ||
| C112 | 0.1 uF | ||
| C113 | 0.1 uF | ||
| C119 | 10 uF 16V | ||
| C120 | 10 uF 16V | ||
| C121 | 10 uF 16V | ||
| C122 | 47 uF 16V | ||
| C123 | 47 uF 16V | ||
| C124 | 47 uF 16V | ||
| C125 | 180 pF | ||
| C131 | 10 uF 16V | ||
| C139 | 150 pF | ||
| CA1 | 10 uF 16V | ||
| CA20 | 100 uF 10V | NP | |
| CON1 | 8-pin DIN, 262 degree | Outputs composite video and RGB on NTSC, RGB only on France | |
| CON2 | 37-pin edge connector | Card slot, same part as used in the Mark III | |
| CON3 | 50-pin edge connector, 2.54 mm pin pitch | Cartridge slot | |
| CON5 | 9-pin D-sub connector | 1P port | |
| CON6 | 9-pin D-sub connector | 2P port | |
| CON7 | 5.5 x 2.1 DC barrel jack | Power input | |
| CP1 | 0.1 uF | ||
| CP2 | 0.1 uF | ||
| CX1 | 180 pF | ||
| D100 | 1S2473 | Reset diode | |
| EM11 | 2200 pF line filter | ||
| EM12 | 2200 pF line filter | ||
| EM13 | 2200 pF line filter | ||
| EM14 | 2200 pF line filter | ||
| EM15 | 2200 pF line filter | ||
| EM16 | 2200 pF line filter | ||
| EM17 | 270 pF line filter | ||
| EM18 | 2200 pF line filter | ||
| EM19 | 2200 pF line filter | ||
| EM21 | 2200 pF line filter | ||
| EM22 | 2200 pF line filter | ||
| EM23 | 2200 pF line filter | ||
| EM24 | 2200 pF line filter | ||
| EM25 | 2200 pF line filter | ||
| EM26 | 2200 pF line filter | ||
| EM27 | 270 pF line filter | ||
| EM28 | 2200 pF line filter | ||
| EM29 | 2200 pF line filter | ||
| FB1 | Ferrite bead, no value | ||
| IC1 | NEC D780C-1 Zilog Z0840004PSC |
CPU; early boards have an NEC chip, later boards Zilog | |
| IC2 | Sony CXK3864 | v1.3 BIOS | |
| IC3 | NEC D4168C-20 | Z80 RAM | |
| IC4 | Sega 315-5216 | I/O controller | |
| IC5 | Sega 315-5124 / Yamaha YM2602 | VDP | |
| IC6 | NEC D4168C-15 | VRAM | |
| IC7 | NEC D4168C-15 | VRAM | |
| IC8 | 7805 | Voltage regulator | |
| IC9 | Sony V7040 | NP | Video encoder |
| IC10 | NP | Populated with a 74LS04 inverter on early prototypes | |
| JG | Ferrite bead, no value | ||
| JV | Ferrite bead, no value | ||
| L31 | 39 uH | NP | |
| L38 | 39 uH | NP | |
| L50 | 100 uH | NP | |
| LED | Green LED | ||
| PAUSE SW | Sega 509-5031 | Same part used in the SG-1000 line and Mark III | |
| POWER SW | Sega 509-5150 | Made by Mitsumi, nearly identical to and compatible with the NES front loader power switch | |
| Q48 | 2SC1740 | NP, base and emitter pads bridged | |
| R5 | 120 ohm | ||
| R6 | 3.3k ohm | NP, VDP end connected by wire to pin 23 of IC9 | Factory resistor value is incorrect, should be 2.2k ohm |
| R7 | 3.3k ohm | NP, VDP end connected by wire to pin 22 of IC9 | Factory resistor value is incorrect, should be 2.2k ohm |
| R8 | 3.3k ohm | NP, VDP end connected by wire to pin 23 of IC9 | Factory resistor value is incorrect, should be 2.2k ohm |
| R9 | 3.3k ohm | NP | Factory resistor value is incorrect, should be 4.7k ohm |
| R10 | 3.3k ohm | NP | Factory resistor value is incorrect, should be 4.7k ohm |
| R11 | 3.3k ohm | NP | Factory resistor value is incorrect, should be 4.7k ohm |
| R15 | 10k ohm | NP | |
| R16 | 1k ohm | NP | |
| R19 | 2.2k ohm | ||
| R24 | 1.3k ohm | NP | |
| R26 | 2.2k ohm | NP | |
| R27 | 75 ohm | NP | |
| R30 | 1.3k ohm | NP | |
| R34 | 6.2k ohm | NP | |
| R35 | 4.7k ohm | NP | |
| R36 | 620 ohm | NP | |
| R40 | 1k ohm | NP | |
| R46 | 2.2k ohm | ||
| R47 | 10k ohm | NP | |
| R102 | 4.7k ohm | ||
| R103 | 4.7k ohm | ||
| R108 | 4.7k ohm | NP | |
| R111 | 4.7k ohm | ||
| R114 | 330 ohm | ||
| R115 | 330 ohm | ||
| R116 | 330 ohm | ||
| R117 | 330 ohm | ||
| R130 | 100k ohm | ||
| RESET SW | Sega 509-5031 | ||
| RF | Mitsumi VA3404 | NP | |
| XTAL | 10.7386 MHz | ||