The 171-5922A is the initial board revision for the Sega Master System II in PAL territories, first introduced in Australasia in late 1990 and Europe in 1991. It is essentially a condensed version of the VA3 revision of the PAL model 1, and is based around the same core hardware as that console, including the use of the 315-5246 VDP and 315-5237 I/O controller. A number of features were removed in order to reduce production costs, such as the Sega Card slot (also meaning no 3-D glasses compatibility), AV and RGB output, expansion port, power LED and Reset button. Both composite video and RGB output can be restored through simple modifications.
All boards have the silkscreened text SEGA IC BD M4Jr. PAL at the lower left corner. Sega did not silkscreen the assembled part number (beginning with "837-"). Very early boards are made of phenolic resin and have exposed copper on the top ground plane[1], while early boards in general have yellow silkscreened text. Most are made of fiberglass (FR-4), have white text, and HASL plating on the ground plane.
Parts List
All resistors are 1/6 W.
| Designation | Value/Name | Notes |
|---|---|---|
| C1 | 82 pF | |
| C2 | 82 pF | |
| C3 | 82 pF | |
| C4 | 82 pF | |
| C5 | 82 pF | |
| C6 | 82 pF | |
| C7 | 33 pF | |
| C8 | 33 pF | |
| C9 | 82 pF | |
| C10 | 82 pF | |
| C11 | 82 pF | |
| C12 | 82 pF | |
| C13 | 82 pF | |
| C14 | 20 pF | |
| C15 | 100 pF | |
| C16 | 180 pF | |
| C17 | 20 pF | |
| C18 | 10 uF 16V | |
| C19 | 33 pF | |
| C20 | 51 pF | |
| C21 | 150 pF | |
| C22 | 150 pF | |
| C24 | 270 pF | |
| C25 | 82 pF | |
| C26 | 0.01 uF | |
| C27 | 0.1 uF | |
| C28 | 0.1 uF | |
| C29 | 0.1 uF | |
| C30 | 180 pF | |
| C31 | 1 uF 50V | |
| C32 | 10 uF 16V | |
| C33 | 12 pF | |
| C34 | 0.01 uF | |
| C35 | 12 pF | |
| C36 | 100 pF | |
| C37 | 180 pF | |
| C38 | 100 uF 10V | |
| C39 | 0.1 uF | |
| C40 | 0.1 uF | |
| C41 | 100 uF 16V | |
| C42 | 100 uF 10V | |
| C43 | 100 uF 10V | |
| C44 | 47 uF 10V | |
| C45 | 33 pF | |
| C46 | 33 pF | |
| C47 | 33 pF | |
| C48 | 33 pF | |
| C49 | 33 pF | |
| C50 | 51 pF | |
| C51 | 27 pF | |
| C52 | 47 pF | |
| C53 | 82 pF | |
| C54 | 0.1 uF | |
| CE | 10 uF 16V | Multiple footprints have this designation but all have the same value |
| CN1 | Burndy PSB4D25S-4R1 | Cartridge slot, 50-pin with 2.54 mm pin pitch |
| CN2 | 9-pin D-sub connector | 1P port |
| CN3 | 9-pin D-sub connector | 2P port |
| CN4 | 5.5 x 2.1 mm barrel jack | DC input |
| CP | 22 nF | Multiple footprints have this designation but all have the same value |
| D1 | 1S2473 | |
| D2 | 1SR-35-100A | |
| 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 | |
| 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 | |
| FB1 | Ferrite bead, no value | |
| FB2 | Ferrite bead, no value | |
| FB3 | Ferrite bead, no value | |
| FB4 | Ferrite bead, no value | |
| FB5 | Ferrite bead, no value | |
| FB6 | Ferrite bead, no value | |
| FB7 | Ferrite line filter, no value | |
| FB8 | Ferrite bead, no value | |
| FB9 | Line filter, 120 ohm impedance | |
| FB10 | Line filter, 120 ohm impedance | |
| IC1 | NEC D780C-1 Zilog Z0840004PSC |
CPU |
| IC2 | Sega MPR-12808 | BIOS with Alex Kidd in Miracle World |
| IC3 | Hitachi HM6265L-90 NEC D4168-15-SG Sanyo LC3664BL-10 |
Z80 RAM |
| IC4 | Sega 315-5237 | I/O controller |
| IC5 | Sega 315-5246 / NEC uPD9004G | VDP |
| IC6 | NEC D4168C-15-SG | VRAM |
| IC7 | NEC D4168C-15-SG | VRAM |
| IC8 | 7805 | Voltage regulator |
| IC9 | Sony CXA1145P | Video encoder |
| JG | Ferrite bead, no value | |
| JV | Ferrite bead, no value | |
| L1 | 12 uH | |
| L2 | 100 uH | |
| L3 | 100 uH | |
| OSC | 53.2034 MHz oscillator | 20 ppm tolerance, same as used in the Mega Drive and VA3 model 1 Master System |
| PAUSE.SW | ALPS SKEVVA | |
| POWER.SW | Hosiden HSW1699-01-010 | Same as used in the model 1 Mega Drive |
| R1 | 4.7k ohm | |
| R2 | 4.7k ohm | |
| R3 | NP | |
| R4 | 100k ohm | |
| R5 | 330 ohm | |
| R6 | 330 ohm | |
| R7 | 330 ohm | |
| R8 | 330 ohm | |
| R10 | 3.3k ohm | |
| R11 | 1k ohm | |
| R12 | 8.2k ohm | |
| R13 | 820 ohm | |
| R14 | 8.2k ohm | |
| R15 | 820 ohm | |
| R16 | 8.2k ohm | |
| R17 | 820 ohm | |
| R18 | 2.2k ohm | |
| R19 | 1.5k ohm | |
| R20 | 2.2k ohm | |
| R21 | 2k ohm 75 ohm (PAL-B VE) |
|
| R22 | 1k ohm | |
| R24 | 1k ohm | |
| R25 | 1k ohm | |
| R26 | 27k ohm | |
| R27 | 10k ohm | |
| R28 | 8.2k ohm | |
| R29 | 2.2k ohm 33 ohm (PAL-B VE) |
|
| R30 | 1.5k ohm | |
| RA1 | 8-pin 4.7k ohm | |
| RF.MOD | Jalco MGB3-UG3601 (PAL-I) Jalco MGB3-VA0102 (PAL-B VV) Mitsumi MDG-UB3622 (PAL-I) Mitsumi MDG-UE3622 (PAL-G) Mitsumi MDG-VE3423 (PAL-B VE) |
