My lovely wife kindly bought me six vintage games consoles for Christmas 2023, all in unknown or non-working condition, including my first SEGA Game Gear.
The SEGA Game Gear is an 8-bit fourth-generation handheld game console, which primarily competed with Nintendo’s Game Boy, the Atari Lynx, and NEC’s TurboExpress. It shares much of its hardware with the Master System, and can play Master System games through the use of an adapter. Sega positioned the Game Gear, which had a full-colour backlit landscape screen with, as a technologically superior handheld to the Game Boy.
Game Gears aren’t particularly rare, and you can pick them up in non-working condition for quite cheap – they go for quite a bit of money when refurbished and modified, though. Their nostalgia value and interesting game library make them quite collectible.
On its arrival, it seemed to be in quite good physical condition. I powered it up with six 1.5V AA batteries, and the power LED lit up and the display backlight worked, but even with a cartridge inserted the unit wouldn’t boot up – it only output a loud buzz from the speaker and displayed some coloured vertical lines on the screen.
The SEGA Game Gear suffers from a major problem: the SMD electrolytic capacitors on the mainboard and audio board, and the through-hole electrolytic capacitors on the power board, all have a habit of failing and physically leaking corrosive electrolyte, which can not only prevent the system from working, but can also cause damage to the circuit boards and the components on them.
I must therefore emphasise: if you have a SEGA Game Gear in original condition, it needs to be serviced! The original electrolytic capacitors need to be replaced. These systems are dying, day by day.
The first step was to disassemble the unit and check over everything inside.
Disassembling the SEGA Game Gear
The Game Gear is easy to dismantle with basic tools: there are six Philips screws holding the rear case in place, four around the perimeter and two inside the battery compartments, and a 4.5mm security screw in the top-centre.
With the case opened, you get your first look inside the console – I was expecting this Game Gear to be original and untouched, but it was pretty clear when opening it up that someone had attempted to “repair” this unit in the past.
Original Game Gear electrolytic capacitors are surface-mount, and look like small black cubes – whereas it seems that someone has already “recapped” this one using a cheap capacitor kit comprising through-hole parts. They hadn’t even cleaned the leaked electrolyte from the original capacitors off the boards, or cleaned up after their rework.
The two halves of the unit are held together with a cable between the mainboard and power board, a cable between the mainboard and the audio board, and a cable between the audio board and speaker.
The mainboard is held into the front case with six small Philips screws around its perimeter (not the four around the rear of the display), and two large Philips screws on each side of the cartridge port.
To get to the rear boards, remove the cartridge shield which is held in place with four small Philips screws; the power board is held in place with a plastic battery terminal shield and two small Philips screws; the audio board is held in place with two small Philips screws.
Mainboard Rebuild
Aluminium electrolytic capacitors are commonly used for filtering, smoothing, and decoupling in both high- and low-voltage electronics. They typically comprise aluminium windings which are coated with a liquid electrolyte, which can dry out over time (negatively affecting the performance of the capacitor, often causing them to fail dead-short), or leak out and cause corrosion to the PCB and surrounding components.
There are several production variants of the Game Gear mainboard, each of which have different electrolytic capacitor values and locations, so take note of which you have.
This one is an early VA0 board with two ASICs (marked “837-7996 IC BD GG MAIN EUROPE”). This is easy enough to recap as it only has 11 SMD electrolytic capacitors:
- C1: 33uF 6.3V
- C3: 10uF 6.3V
- C6: 10uF 6.3V
- C31: 100uF 6.3V
- C35: 4.7uF 35V
- C37: 68uF 6.3V
- C39: 100uF 4V
- C44: 0.47uF 50V
- C45: 0.47uF 50V
- C48: 10uF 6.3V
- C49: 22uF 6.3V
The original parts can be removed using a hot air rework station with kapton tape and aluminium foil to protect the surrounding areas, or by carefully twisting them off using needle-nose pliers (this technique may not be suitable if the pads are damaged, as they could delaminate from the board).
The pads can then be cleaned up using new leaded solder and either desoldering braid or a desoldering station. Finally, the board should be thoroughly cleaned to remove any leaked electrolyte and leftover flux, using isopropyl alcohol and ESD-safe brushes. I also gave the board a run in my ultrasonic bath.
One of the pads had been damaged, and needed to be repaired with wrapping wire.
The new parts can then be fitted. The originals were aluminium electrolytic capacitors with a liquid electrolyte, however its very common for those recapping classic Game Gears to use ceramic capacitors, which don’t have an electrolyte and aren’t polarised – they are microphonic, though, so are not appropriate for use in some applications. A good equivalent to aluminium electrolytic capacitors is tantalum electrolytic capacitors – these use a solid electrolyte, meaning that they will not physically leak.
When substituting electrolytic capacitors, the capacitance needs to be the same, and the voltage rating can be the same or higher (within reason) – when you’re going through all this effort to recap something, be sure to use high-quality replacements.
I couldn’t find any commercially available tantalum capacitor packs for this version of the Game Gear mainboard, so I just made up my own by noting the specifications of all of the electrolytic capacitors on the board, and ordering a set of high-quality known-brand parts.
I used a mixture of ceramic and tantalum electrolytic capacitors – ceramics for the smaller capacitance values (< 10uF), and tantalums for the larger capacitance values (>= 10uF).
When fitting new electrolytic capacitors, you must take care to ensure that the value, voltage rating, and orientation of the new capacitor are correct – electrolytic capacitors are polarised, so must be installed the correct way around, else they’ll get hot when powered on (and probably explode). The polarity is marked on the case: for aluminium electrolytic capacitors, the negative side is usually shown by a white stripe (for through-hole) or a black bar (for SMD); for tantalum capacitors, the positive side is usually shown by an orange or white bar (for SMD). This catches a lot of people out!
You can’t always trust the orientation markings on the PCB silkscreen (if it even has them, not all boards do), as sometimes mistakes were made in the design from the factory (take the PCB layout of the audio circuit on the Commodore CD32, for example), so care must be taken to match the orientation of the new capacitor with the original. Make sure to take lots of “before” pictures for reference.
I also cleaned all of the sockets and controls using contact cleaner.
Audio Board Rebuild
The audio board is a similar story to the mainboard, with SMD electrolytic capacitors.
There are several production variants of the Game Gear audio board, each of which have different electrolytic capacitor values and locations, so take note of which you have.
This one is a later audio board (marked “837-7998 IC BD GG SOUND EUROPE”). This is easy enough to recap as it only has 5 SMD electrolytic capacitors:
- C1: 100uF 6.3V
- C2: 100uF 6.3V
- C3: 100uF 6.3V
- C5: 47uF 4V
- C7: 47uF 4V
The audio board also had some damaged/laminated pads, which could be bridged using the new physically longer components.
I also cleaned all of the sockets and controls using contact cleaner.
Power Board Rebuild
The power board is a similar story to the mainboard and audio board, but with through-hole electrolytic capacitors instead of SMD.
There are several production variants of the Game Gear power board, each of which have different electrolytic capacitor values and locations, so take note of which you have.
This one is a later audio board (marked “837-7399-01 IC BD GG POWER EUROPE”). This is easy enough to recap as it only has 3 through-hole electrolytic capacitors:
- C5: 22uF 35v
- C11: 100uF 25v
- C13: 820uF 6.3v
Only the smaller-value capacitors on the power board tend to leak – you can probably get away with just replacing these, however all aluminium electrolytic capacitors have a limited service life, so I replaced them all.
I usually remove each capacitor one-by-one using my desoldering station (a Duratool D00672) and immediately install a replacement, then clean up all the remaining flux residue or heat marks using 99.9% IPA.
The power board had some damaged/scorched vias from its prior “repair”, so I checked that everything was still connected correctly.
Post-Repair Testing
I tested the Game Gear following its recap – the screen still didn’t work (same symptoms as before, nothing displayed except for some coloured vertical lines), but the system seemed to boot correctly from cartridge as you could hear in-game audio.
Apparently, the original Game Gear display is quite unreliable, and a common failure point – it uses a fluorescent backlight which draws a lot of power and gets hot, which can bake the four display driver ICs that are part of the screen’s flexible circuit board.
Because it’s such a common failure point, there are a diverse range of aftermarket Game Gear display replacement kits available. I bought a display kit on eBay which looked good, as it included connectors for the mainboard, and a new glass screen cover.
Display Modification Installation
The seller of the display provided some basic user manuals for its installation.
The first step is to remove the original display, which is held to the mainboard with four small Philips screws, and its ribbon cable – this comes off easily using a hot air gun and a pair of tweezers, but make sure not to pull too hard else you’ll damage the pads below.
This kit also requires that several components be removed from a twin-ASIC mainboard:
- Nine SMD resistors: R29 (if fitted), R30, R32, R33, R34, R38, R41, R43, and R44.
- Four SMD transistors: Q2 (if fitted) and Q6 (both on the mainboard topside), and Q3 and Q4 (both on the mainboard underside).
- Two through-hole capacitors: C32 and C33.
- One inductor coil: L2.
- One transformer: T1 (optional).
- The fluorescent lamp (FL) and its two thermal fuses (FU1 and FU2).
For the VA0 twin-ASIC mainboard, a jumper wire needs to be installed between T10 and T11; for the VA1 single-ASIC board, a jumper wire needs to be installed between the bottom of R23 and T10..
Now is a good time to check Vcc on the Game Gear to ensure that it’s in-spec for your new display (i.e. < 5.45Vdc), else this could be damaged.
This kit now required that a flex cable be installed on the connector for the original display, making sure to line up the pin numbers on the flex cable correctly. I couldn’t get the solder to flow across its straight edges, so I jumped each pin with some wrapping wire, then fitted some kapton tape over the top to help protect the connections.
The display driver board can then be attached in-place with solder – I soldered all four corners to help with the mechanical strength of the mainboard. I connected up the flex cable to the T1 connector on the display driver board before locating the display driver board, as it isn’t accessible afterwards.
The two flying leads on the display driver board can then be connected up:
- T2
- The backlight (black) wire can be removed (unless you’re fitting a VGA connector).
- The clock (red) wire should be connected to FB1, cut as short as possible.
- T3
- VA0 Twin-ASIC Board
- P1 (red) should be connected to pin 2 of the brightness control.
- P2 (black) should be connected to pin 3 of the brightness control.
- 2 (yellow) should be connected to the right side of C30.
- 3 (green) should be connected to the left side of C29.
- 1 (blue) should be connected to the bottom of C28.
- VA1 Single-ASIC Board
- P1 (red) should be connected to pin 2 of the brightness control.
- P2 (black) should be connected to pin 3 of the brightness control.
- 2 (yellow) should be connected to the right side of C38.
- 3 (green) should be connected to the left side of C37.
- 1 (blue) should be connected to the bottom of C36.
- VA0 Twin-ASIC Board
It was then time to test the new display before reinstalling everything in the case – I powered it up with a Star Wars cartridge, and it seemed to work perfectly!
Case Modifications
The case requires some minor modifications to fit the new screen: the plastic screw standoff for the security bit needs to be removed with a pair of cutters; the rubber seal between the original display and the front case needs to be removed, and the four small plastic stems that hold this in place need to be trimmed off; the four large prongs on the rear cartridge shield need to be removed with a pair of cutters.
The new screen can then be aligned and fitted using the double-sided foam tape in the kit.
I also removed the original plastic display cover, cleaned behind it, cleaned off the original adhesive using 99.9% IPA, and fitted the glass display cover that was included in the kit. It’s not perfect (there are better quality remakes available), but it’s far better than the original!
The three boards and the cartridge shield could then be reinstalled in the front and rear case, in the opposite order to their disassembly.
The three boards and the speaker can then be reconnected.
With everything reinstalled, the new screen and cover looked fantastic.
Battery Modification Installation
The SEGA Game Gear uses six 1.5V AA batteries, which are quite heavy, usually can’t be recharged, and don’t last for a very long time – especially with an original display.
A common Game Gear modification is to fit a rechargeable battery kit, such as the RetroSix “CleanJuice GG” – this includes a modern replacement power board with a USB-C input, and two rechargeable LiPo battery packs.
A factory case requires minor modifications so the battery packs can be fitted: the original AA battery terminal cables can be snipped out and the battery contacts removed; a set of the contact holders can then be snipped out to make space for the new battery packs.
The new battery packs can then be fitted, feeding the cables through gaps in the case.
The new power board is a straight swap for the original, and can then be connected to the two new battery packs – the connectors only fit one way around.
To get the new power board to work correctly with my new screen, I had to disable the 34V output, enable the VREF bypass, and reduce the on delay to a minimum.
Reassembly and Testing
After its recap, screen modification, and battery modification, the Game Gear looked and worked fantastic! I even bought an SD card loader cartridge to try out some new games.
Great write up! You covered everything. I have been wanting to tackle this update/upgrade for a while, but it’s like 8 different updates to do everything and I always moved on to something else before I got all the mods researched and mapped out (mainly due to all the unknowns on off-the-shelf parts that might or might not work). You’ve done all that and conveniently put it all in one place! Thanks for the great content and solid research! Well done!!