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Hello,

Recently I've started to repair Game Gears I bought some time ago. Unfortunately I can't call it success. One has corroded traces so I left it for parts, the other one works but there's no image on screen - contrast wheel works thought. It should be good for consolized version. And finally the last one...

It's 1 ASIC version. Clean inside, no signs of leaked electrolyte or so. I followed usual route and removed old caps, cleaned pads, soldered new caps on power, sound and main board. Looks pretty but power led stays red for one or two seconds and turns off. I checked it with other power board that works. Nothing. I tgought it might be because of fluorescent tube, so I removed it and both fuses. Still the same. Since I was that close I also removed C69, T1, L2 and C70 to make it ready for DSi backlight (L2 bridged). Still nothing. Started checking connection on caps - everything looks ok. Spent last few hours googling for answer but looks like nothing's there.

Anyone could point me what should I check next? I really want to repair it...

I had a similar problem. Does the game load at all before if shuts off? If not, check the pins for shorts. Good luck! The Game Gear is one of my personal favorites(just look at my name).

Nope, doesn't load at all. It powers off immediately with or without any cartridge. I checked pins anyway - they look the same way as in working one.

Hm, I suppose it might be one of components but I'm completely clueless where I should look. Some resistor maybe is blown or so?

Ive just had a quick look at the circuit diagram i found for the 2 asic version and im assuming 1 of two things are happening.

1) power supply is over loaded and going into protection shut down.

2) asic is not able to measure battery voltage and assuming battery is going flat and shutting everything down.

Get a multimeter out and see what the power supply is doing. On the power cable pin 1 should be +5v, pin 6 should be 1.28v, pin 7 should be battery voltage (around 9v) and pin 9 should be 34v. Pins 3,4 and 5 are all ground.

If the power supply is being over loaded then it will shut down on its own. You can probably rule this out by checking each supply voltage and see whats happening before it shuts down. If one of the voltages are low then something is wrong and needs looking into.

If that looks fine then you want to look at the battery voltage measurement circuit. I don't have a 1 asic circuit diagram but on the 2 asic model its fairly straight forward, just 3 resistors a capacitor and a diode. The cap is an electrolytic (0.22uf 63v on the 2 asic) so if youve changed all the caps then it would be worth checking this area of the circuit for any shorts or lifted resistors.

I normally would say to pull the backlight, but you already did. Did you replace the power board caps? They don't fail quite as often, but they are still electrolytic, so you might want to pay the couple of bucks to change them.

Thanks for replies, I've checked power board with multimeter and it works properly. All voltages are as expected. I've also tested it with 2 asic working board to make sure.

As for battery voltage measurement circuit - where do I find it? I mean, I've 2 asic board but it doesn't have 0.22uF 63V capacitor - do you mean 22uF 6.3V - C49 = C43 on 1 asic board? If so, I've already checked that area. Unfortunately it looks like new. I didn't make any damage there. ;) It's actually the most frustrating thing that best looking board seems to be unusable. Any more hints?

Author	Message
st Joined: 16 Nov 2005 Posts: 6	Game Gear turns off :( Posted: Mon Jun 29, 2015 2:53 pm
st Joined: 16 Nov 2005 Posts: 6	Hello, Recently I've started to repair Game Gears I bought some time ago. Unfortunately I can't call it success. One has corroded traces so I left it for parts, the other one works but there's no image on screen - contrast wheel works thought. It should be good for consolized version. And finally the last one... It's 1 ASIC version. Clean inside, no signs of leaked electrolyte or so. I followed usual route and removed old caps, cleaned pads, soldered new caps on power, sound and main board. Looks pretty but power led stays red for one or two seconds and turns off. I checked it with other power board that works. Nothing. I tgought it might be because of fluorescent tube, so I removed it and both fuses. Still the same. Since I was that close I also removed C69, T1, L2 and C70 to make it ready for DSi backlight (L2 bridged). Still nothing. Started checking connection on caps - everything looks ok. Spent last few hours googling for answer but looks like nothing's there. Anyone could point me what should I check next? I really want to repair it...

Capt. 2110 Joined: 27 Apr 2014 Posts: 281 Location: Texas	Posted: Fri Jul 03, 2015 3:49 pm
	I had a similar problem. Does the game load at all before if shuts off? If not, check the pins for shorts. Good luck! The Game Gear is one of my personal favorites(just look at my name).

st Joined: 16 Nov 2005 Posts: 6	Posted: Sat Jul 04, 2015 12:18 pm
st Joined: 16 Nov 2005 Posts: 6	Nope, doesn't load at all. It powers off immediately with or without any cartridge. I checked pins anyway - they look the same way as in working one. Hm, I suppose it might be one of components but I'm completely clueless where I should look. Some resistor maybe is blown or so?

wasup Joined: 05 Nov 2014 Posts: 435 Location: Auckland - NZ	Posted: Mon Jul 06, 2015 12:48 pm
	Ive just had a quick look at the circuit diagram i found for the 2 asic version and im assuming 1 of two things are happening. 1) power supply is over loaded and going into protection shut down. 2) asic is not able to measure battery voltage and assuming battery is going flat and shutting everything down. Get a multimeter out and see what the power supply is doing. On the power cable pin 1 should be +5v, pin 6 should be 1.28v, pin 7 should be battery voltage (around 9v) and pin 9 should be 34v. Pins 3,4 and 5 are all ground. If the power supply is being over loaded then it will shut down on its own. You can probably rule this out by checking each supply voltage and see whats happening before it shuts down. If one of the voltages are low then something is wrong and needs looking into. If that looks fine then you want to look at the battery voltage measurement circuit. I don't have a 1 asic circuit diagram but on the 2 asic model its fairly straight forward, just 3 resistors a capacitor and a diode. The cap is an electrolytic (0.22uf 63v on the 2 asic) so if youve changed all the caps then it would be worth checking this area of the circuit for any shorts or lifted resistors.

Capt. 2110 Joined: 27 Apr 2014 Posts: 281 Location: Texas	Posted: Mon Jul 06, 2015 3:39 pm
	I normally would say to pull the backlight, but you already did. Did you replace the power board caps? They don't fail quite as often, but they are still electrolytic, so you might want to pay the couple of bucks to change them.

st Joined: 16 Nov 2005 Posts: 6	Posted: Wed Jul 08, 2015 5:20 pm
st Joined: 16 Nov 2005 Posts: 6	Thanks for replies, I've checked power board with multimeter and it works properly. All voltages are as expected. I've also tested it with 2 asic working board to make sure. As for battery voltage measurement circuit - where do I find it? I mean, I've 2 asic board but it doesn't have 0.22uF 63V capacitor - do you mean 22uF 6.3V - C49 = C43 on 1 asic board? If so, I've already checked that area. Unfortunately it looks like new. I didn't make any damage there. ;) It's actually the most frustrating thing that best looking board seems to be unusable. Any more hints?

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