Here you will find repair resources for the SEGA Game Gear Majesco 171-7923A model. Currently there is still some work-in-progress for the schematics, but we will keep updating it!

GAME GEAR MAIN USA 171-7923A Board scans

BOM

I disassembled all parts by hand and measued them with my LCM meter. So far this is the result of the GameGear Majesco BOM.

Designator	Value	Package	Description
C1	33uF/6V	ECAP 8x4.5mm
C2
C3
C4	33nF	0805
C5	NC	0805
C6	68pF	0805
C7	NC	0805
C8
C9
C10
C11	270pF	0603
C12	270pF	0603
C13	270pF	0603
C14	270pF	0603
C15	270pF	0603
C16	270pF	0603
C17	270pF	0603
C18	270pF	0603
C19	270pF	0603
C20	2.2nF	0805
C21	2.2nF	0805
C22	2.2nF	0805
C23	2.2nF	0805
C24	2.2nF	0805
C25	2.2nF	0805
C26	2.2nF	0805
C27	22pF	0805
C28	22pF	0805
C29	120nF	0805
C30	120nF	0805
C31	10uF / 6V	ECAP 6x3.5mm
C32	120nF	0805
C33	10uF / 6V	ECAP 6x3.5mm
C34	120nF	0805
C35	10uF / 6V	ECAP 6x3.5mm
C36	22uF / 6V	ECAP 6x4.5mm
C37	10uF / 6V	ECAP 6x3.5mm
C38
C39	10uF / 50V	ECAP 10x4.5mm
C40	47uF / 6V	ECAP 8x4.5mm
C41	22uF / 6V
C42	10uF / 50V	ECAP 10x4.5mm
C43	1uF / 50V	ECAP 6x3.5mm
C44
C45	120nF	0805
C46
C47	10uF / 50V	ECAP 10x4.5mm
C48
C49	1uF / 16V	1812
C50	1uF / 16V	1812
C51	1uF / 16V	1812
C52	1uF / 16V	1812
C53	8.2nF	0805
C54	8.2nF	0805
C55	100uF / 6V	ECAP 13x4.5mm
C56	33nF	0805
C57
C58
C59	33nF	0805
C60
C61	NC	0805
C62
C63
C64	270pF	0603
C65	270pF	0603
C66	270pF	0603
C67
C68
C69	270pF	0603
C70
C71	10uF / 6V	ECAP 6x3.5mm
C72
C73	100pF	0805
C74	100pF	0805
C75
C76	470nF	0805
C77	470nF	0805
C78	470nF	0805
C79	470nF	0805
R1	4.7K	0603
R2	4.7K	0603
R3	4.7K	0603
R4	4.7K	0603
R5	470K	0603
R6	470K	0603
R7	470K	0603
R8	470K	0603
R9	470R	0805
R10	4.7K	0805
R11	4.7K	0805
R12	470R	0603
R13	470R	0603
R14	470R	0603
R15	470R	0603
R16	470R	0603
R17	470R	0603
R18	470R	0603
R19	470R	0603
R20	470R	0603
R21	1.8K	0805
R22	51R	0805
R23	9.1K	0805
R24	3K	0805
R25	1.1K	0805
R26	10K	0805
R27	10K	0805
R28
R29
R30
R31	33K	0805
R32	22K	0805
R33	100K	0805
R34	180K	0805
R35	27K	0805
R36	150K	0805
R37	20K	0805
R38	100K	0805
R39
R40
R41
R42
R43
R44
R45	18K	0805
R46	18K	0805
R47	18K	0805
R48	2.2K	0805
R49
R50	16K	0805
R51	16K	0805
R52	16K	0805
R53	47K	0805
R54	47K	0805
R55	1K	0805
R56	1K	0805
R57	1K	0805
R58	1K	0805
R59	10K	0805
R60	10K	0805
R61	1.8K	0805
R62	1.8K	0805
R63	130K	0805
R64
R65
R66
R67	4.7K	0805
R68	1K	0805
R69
R70
R71
R72
R73
R74
R75
R76
R77
R78
R79
R80	150K	0805
R81	20K	0805
R82	100K	0805
R85	47K	1206
Q1
Q2	ZR
Q3	1VS
Q4	ZR
Q5	BR
Q6	ZR
Q7
Q8	ZR
Q9	ZR
Q10	ZR
Q11	ZR
Q12	XK
Q13	XK
Q20	ZR
Q21	BR
D1	B3
D2	MO
D3	MS
D4	ZR	SOT-23
D5	MS
D6	B3	SOT-23
D7
D8
FU1
FU2
L1	FERRITE BEAD
L2	100uH
L3
L4
IC1	SEGA 315-5682
IC2	HM65256BLFP-10T
IC3	KM6264BLG-10
IC4	10358
VR1
X1	32.21590MHz

 

SEGA 315-5682 Pinout

The SEGA 315-5682 chip is used by the VA4 / VA5 and Majesco variants. So far I have traced back the majority of the traces and made the following pinout. Most of the pinout is based on the VA1 SEGA 315-5535 chip. Still work in progress!

No	Pin Name		No	Pin Name		No	Pin Name		No	Pin Name
1	Vdd		37	GND		73	Vdd		109	GND
2			38	NGG		74			110	CSYNC
3			39	NTV		75			111	NUP
4			40	NLCD		76			112	NDW
5			41	A?		77			113	NLE
6			42	TPR2		78			114	NRI
7			43	TPR1		79			115	TST2?
8			44			80			116	TST1?
9			45			81			117	TST0?
10			46			82	GND (A)		118	NTSC
11			47			83	VONF		119	SEC
12			48			84	VRES		120	PC6
13			49			85	VREF		121	PC5
14			50			86	SNDR		122	PC4
15			51			87	SNDL		123	PC3
16			52			88	SND1		124	PC2
17			53			89	SND2		125	PC1
18	GND		54			90	SND3		126	PC0
19			55			91	SNDN		127	CRAM?
20			56			92	Vdd (A)		128	IRQ?
21			57			93	GND (A)		129	NWR?
22			58			94	SDO1		130	NRD?
23			59			95	SDO2		131	RST
24			60			96	SDO3		132	488?
25			61			97	SDO4		133	HBK?
26			62			98	Vdd (A)		134	VBK?
27			63			99	SAMP		135	CP0?
28			64			100	SPON		136	Vdd
29			65			101	HSYN		137	XTL2
30			66			102	VSYN		138	XTL1
31			67			103	INT		139	GND
32			68			104	NMI		140	NLED
33			69			105	WAIT		141	RSH?
34			70			106	NBRQ		142	NJAP?
35			71	GND		107	NBAK?		143	GND
36	Vdd		72	GND		108	Vdd		144	GND