SEGA Game Gear (837-7996) Refurbishment:
I had been looking for a cheap Game Gear to work on for quite a while and after putting feelers out locally I was presented with a broken one that had come out of an attic of a friends acquaintance and asked to give him an offer if I wanted it.
I was allowed to look over it for a few days and found that I could get it to power on for brief periods of time and if I tilted it to very specific angles I could just about make out video albeit with some white horizontal dead pixels in the screen, so I knew a replacement screen would most likely be necessary:
Sadly no sound was coming out of the speaker or the headphone jack, so I opened it up to check on the capacitors and it was obvious they had gone bad and where leaking so I wasn’t too concerned:
The power PCB and the Motherboard PCB didn’t seem to be in too bad shape and hardly any noticeable damage so I decided I wouldn’t mind giving this a go so offered £10 which was eagerly accepted.
Game Gears are notorious for having bad capacitors so a recap was in order.
Working on the Audio PCB:
I wanted to ensure that I could get the audio working before I invested too much so I removed the leaking capacitors from the dedicated Audio PCB using a hot air station and then cleaned up the pads:
Unfortunately the positive capacitor leg pad for C3 had lifted due to corrosion, however because the trace itself was not broken I was able to use super glue to tack it back down onto the PCB.
Audio Board Capacitor Summary:
C1 - 100µf (6.3v) ~ TESTED: 116µf but LEAKING 6.3 (Dia.) x 5.8mm
C2 - 100µf (6.3v) ~ TESTED: 114µf but LEAKING 6.3 (Dia.) x 5.8mm
C3 - 100µf (6.3v) ~ TESTED: 111µf but LEAKING 6.3 (Dia.) x 5.8mm
C5 - 47µf (4v) ~ TESTED: 1.65µf and LEAKING 4 (Dia.) x 5.8mm
C7 - 47µf (4v) ~ TESTED: 0.27µf and LEAKING 4 (Dia.) x 5.8mm
Unlike many other I wanted to replace the capacitors with the same type of SMD capacitors so I had to measure their dimensions and found appropriate Panasonic replacements with part numbers EEEFPJ470UAR & EEEFK1C101P which were soldered in and audio was restored:
I now removed the capacitors on the dedicated power PCB:
Power Board Capacitor Summary:
C5 - 22µf (35v) ~ TESTED: 21.18µf
C11 - 100µf (25v) ~ TESTED: 113µf
C13 - 820µf (6.3v) ~ TESTED: 815µf but LEAKING 10 (Dia.) x 12.5mm
I then replaced them with brand new ones:
If after recapping this power board you are still having power issues you should replace the Fujitsu MB3775 IC which is a switching power regulator. However all the voltages were reading fine for me so I did not need to do this, but it is probably recommended if the IC is showing any signs of burn in damage.
While at first glance the capacitors on the main Game Gear board looked to be okay on closer inspection you can see some corrosion on the solder joints:
However once they were removed you could see the damage was much worse:
I had to resort to heavy usage of a fibre glass pen to clean up the pads so they were good enough to re-tin them for the recap. Since the originals are so small it is hard to find replacement electrolytic capacitors that can cleanly replace them:
Due to the clearance available you can take some liberties and use up to 6.3mm diameter capacitors and aim to find 5-6mm length capacitors that can easily fit in the original positions. However for the C44 and C45 0.47µf capacitors I was unable to locate small enough capacitors in stock anywhere so I had to leave the capacitor legs longer to allow me to position them flat in new positions that wouldn’t obstruct the closing of the case:
Also even with a 5mm length capacitor at position C6 it will end up resting on top of the SEGA ASICs so I left the legs longer and bent them to allow a better resting position for it as well:
Motherboard Capacitor Summary:
C1 - 33µf (6.3v) ~ TESTED: 310nf
C3 - 10µf (6.3v) ~ TESTED: 11µf
C6 - 10µf (6.3v) ~ TESTED: 11µf
C31 - 100µf (6.3v) ~ TESTED: 0.03nf and LEAKING
C35 - 4.7µf (35v) ~ TESTED: 1.36 and LEAKING
C37 - 68µf (6.3v) ~ TESTED: 0.03nf
C39 - 100µf (4v) ~ TESTED: 122µf
C44 - 0.47µf (50v) ~ TESTED: 1.15nf and LEAKING
C45 - 0.47µf (50v) ~ TESTED: 71nf and LEAKING
C48 - 10µf (6.3v) ~ TESTED: 8.4µf
C49 - 22µf (6.3v) ~ TESTED: 0.23nf and LEAKING
After I confirmed everything was working after the recap, I used my hot air station on the ribbon cable connecting the original screen to the PCB and removed it along with the CFL back-light and various components that would no longer be required for the replacement screen: