Game Gear:Game Gear Model Differences
Although the basic design of the Game Gear remained largely the same during its lifespan, there are a number of different revisions which range from simple cosmetic differences to redesigned internals.
Board Revisions
VA0 (1990-1993, All Regions)
This is the initial board revision of the Game Gear, and is often known as the "twin ASIC" version as it is the only Game Gear revision to have a separate VDP (Video Display Processor) and SCA (Standard Cell Array), which are two SMD chips located near the speaker. It is also the only Game Gear revision to have a discrete Z80 CPU.
Board Part Numbers
- 837-7398-0x (Japan)
- 837-7719-0x (US)
- 837-7996 (Europe)
VA1 (1992-1996, All Regions)
The VA1 was gradually introduced for all regions during 1992 and totally replaced the VA0 by 1993. In this revision, the Z80, VDP and SCA were combined into a single ASIC (315-5535), reducing production costs. This was the final board revision for Europe and Japan.
VA1 boards began being phased in with the following serial numbers:[1]
- 020019501 (Europe)
- 020168498 (Canada)
- 020176537 (US)
- B20135204 (North America)
- B30000001 (Europe)
- K20117921 (North America)
- K37000001 (Europe)
- P31000001 (North America)
- P31020001 (Europe)
Board Part Numbers
- 837-8560 (Japan)
- 837-9024 (North America)
- 837-9130 (Europe)
VA4 (1993-1994, North America)
This unusual revision only appeared in North American systems and uses a different ASIC (315-5682) than the VA1. Some components, namely the audio preamp and video RAM, were also relocated to the front of the board. The LCD used in the VA4 is completely different than the VA0 and VA1, with two smaller ribbon cables coming from the right-hand side of the screen. As a result, screen mods intended for the VA0 and VA1 are not compatible. Sega also changed the connectors for the power and sound PCBs, and ones intended for earlier revisions cannot be used on a VA4 without modification.
Game Gears with this board will have the model number 2110K.
VA5 / 171-7923A (1994-1996 and 2001, North America)
On this revision, the audio preamp and video RAM were moved back to the rear of the board and the LCD was changed again, this time using a single ribbon cable as on the VA0 and VA1. Despite this, it is still incompatible with screen mods intended for those revisions. Like the VA4, Sega used different connectors for the power and sound PCBs so earlier ones are not compatible without modification. This revision is also incompatible with the TV Tuner.
Majesco Game Gears (detailed below) used a slight variant of the VA5 known as the 171-7923A. All Game Gears with a VA5 board, including Majesco units, have the model number 2110G.
Cosmetic Differences
Colorways
Although the vast majority of Game Gear units are a dark gray/black color, Sega did offer the Game Gear in different colors for both the Japanese and North American markets.
Conductive Paint
On North American and European systems, the inside of the shell was coated with conductive paint in order to reduce EMI. Earlier units have an aluminized coating while later systems use a brown-colored paint instead. Japanese systems have bare plastic on the inside and do not have conductive paint.
AC Adapters
European and Japanese systems use the same tip negative AC adapter as the Master System and model 1 Genesis/Mega Drive, while US systems use the same tip positive EIAJ-03 AC adapter as the model 2 Genesis/Mega Drive.
Screen Lens
Older Game Gears have a completely flat screen lens while most systems have a curved "bubble" lens, a change which occurred during 1992. This can also be used as a very rough way to determine if a system has a VA0 or VA1 board; systems with a flat lens (assuming it has not been replaced with an aftermarket one) will always have a VA0 board, though some older systems with a bubble lens will also have a VA0 board.
TMSS
During the VA1's production run, Sega began implementing TradeMark Security System functionality, presumably in an attempt to deter unlicensed games as Sega had previously done with the Genesis/Mega Drive. Although the TMSS ROM was always part of the VA1's ASIC, Sega did not start implementing it until 1993, starting with US and European units. European Game Gears with TMSS also have a different model number, MK-2110-50 instead of 2110-50. In Japan, TMSS began appearing during 1994. TMSS is also present on the VA4 and VA5 board revisions.
On all applicable board revisions, the TMSS screen can be disabled by shorting "J1" on the motherboard, and Sega did install a 0 ohm jumper at this location for VA1 units that did not have TMSS.[2]
Majesco Game Gear
US-based distributor Majesco rereleased the Game Gear in early 2001, several years after Sega had officially discontinued the system. These units have a number of cosmetic differences, the most notable being the monochrome ovals on the screen lens (these are tricolored on original run units). The power switch is also black instead of red, the Start button has more of a purplish tinge, and both the serial and model number labels are made of white paper instead of foil. All Majesco units have the 171-7923A board revision. Majesco units are generally less susceptible to capacitor leakage, but they are not immune to this common issue and it is still recommended to recap these systems regardless.
Links
https://segaretro.org/Sega_Game_Gear
https://en.wikipedia.org/wiki/Game_Gear
https://www.retrorgb.com/gamegearversions.html
https://console5.com/techwiki/index.php?title=Game_Gear