Subsituting the 68uF Cap on a Game Gear

[Kouen Hasuki]

Hello!

Sorry this is my first post here though I do plan to be more active and am looking for a little guidance.

I have a European Sega Game Gear here (837-7996) and have been replacing the caps more as a bit of a hobby side thing than anything else, recently I have had a clear out of some electronics and after testing salvaged plenty of caps I have reused perfectly fine in the unit since before starting it had no sound out of the main speaker and the backlight was gone out on it as many GG's do and the caps I have done have brought it back to life.

However it's still not up to its normal full brightness like my other American single ASIC one and I have only 1 Capacitor to change the C37 (68uF @ 6.3v)

What I am wondering is this, is it possible for me to substitute the capacitor for another? Or does that one capacitor have to be dead on 68uF? All the other caps in the game gear have been changed with correctly rated caps at the same or higher voltage.

Many thanks in advance

[nightrnr]

Nope, I'm afraid not.

As you said, it can be the same or higher voltage, but the "micro farad" rating for the cap must be accurate.

Also, yes you can reuse caps from other devices, but you always have the chance of running into a bad cap and then wasting a lot of work when you have to replace them all to find out what one was bad. You never know how much life is left in them either.

Caps are cheap though; buy a group of them and you are set for future replacements too.

[Hobie-wan]

I concur.

[Kouen Hasuki]

Nope, I'm afraid not.

As you said, it can be the same or higher voltage, but the "micro farad" rating for the cap must be accurate.

Also, yes you can reuse caps from other devices, but you always have the chance of running into a bad cap and then wasting a lot of work when you have to replace them all to find out what one was bad. You never know how much life is left in them either.

Caps are cheap though; buy a group of them and you are set for future replacements too.

Oh, Don't get me wrong I agree! though this is more of a Practice / Project unit since it has a defect on the LCD Screen anyway (though I may make a topic on it at some point) If I was recapping my Best unit that's near mint condition with the improved LCD Screen I would use all new High Quality caps Since this is more a Junker I didn't mind lowering the bar some

In the end I used a 22 and a 47 in Parallel which would be within a small margin of variance and that worked fine (Ran the GG for an hour after to be sure)

I have noticed the Tube is going out on it so I'm next planning to LED mod it

[nightrnr]

In the end I used a 22 and a 47 in Parallel which would be within a small margin of variance and that worked fine (Ran the GG for an hour after to be sure)

Totally forgot that you could do that!
More trouble that it's worth to me though. Also, I know the Game Gear is roomy, but I try not to press my luck.
In any case, it's a clever "make do" solution and I commend you for it.

I have noticed the Tube is going out on it so I'm next planning to LED mod it

Neato! I've done some myself.
If you want any insights to the mod, let me know. I have my own slight variation using 4 LEDs. It works out pretty well, and you only lose about an hour of battery life vs the 2 LED option (like 13 hours instead of 14 hours with alkalines).

Damn, this almost motivates me to get back into fixing and tinkering with them again.

[Kouen Hasuki]

In the end I used a 22 and a 47 in Parallel which would be within a small margin of variance and that worked fine (Ran the GG for an hour after to be sure)

Totally forgot that you could do that!
More trouble that it's worth to me though. Also, I know the Game Gear is roomy, but I try not to press my luck.
In any case, it's a clever "make do" solution and I commend you for it.

I have noticed the Tube is going out on it so I'm next planning to LED mod it

Neato! I've done some myself.
If you want any insights to the mod, let me know. I have my own slight variation using 4 LEDs. It works out pretty well, and you only lose about an hour of battery life vs the 2 LED option (like 13 hours instead of 14 hours with alkalines).

Damn, this almost motivates me to get back into fixing and tinkering with them again.

You got me curious now about the 4 LED mod!

I have 50 37k ohm 1/4w Resistors coming and 20 white 5mm LED's from China so I should be good

[nightrnr]

Okay, so I've been meaning to do a tutorial of some kind for my tweaks on the mod (and trust me when I say simplicity is the goal, so it's not any more difficult ) ...
...but not sure when I'll get around to it. Hopefully, I can take pictures soon and post them here or on my old sale thread. I do intend to, but don't hold your breath, in case my motivation fails me.

But there's nothing extensively different to it actually.
Basically, I just have 2 LEDs on each side, one bending upward, one bending down. It seems to add some extra brightness and spread the light a little more evenly, but it's tricky to get them just right so that the bright spots (unavoidable, but not unpleasant) are even and symmetrical.

In parallel, the LEDs share the positive legs on one wire and the negative legs on the other. You use electrical tape or hot glue to ensure that there are no shorts. Then it's just a matter of placing them in the light shield and soldering the appropriate points.
I think I used an 18ohm 1/2 watt resistor for that (the 2-LED used a 33ohm 1/4 watt).

You can still use the 37ohm resistor, but it might be slightly dimmer than if you used something lower. I'm told a little higher or lower won't make a big difference.
According to a resistor calculator I just used, around 22 ohms is optimal for 4 LEDs in parallel. So you are high and I am low; but again, probably close enough. I might even go back to the 33ohms as I think the 1/4 watt is fine too.

[Kouen Hasuki]

Aye, I decided to go to 37ohm's to be a bit more conservative and try to make sure I don't burn out the LED's, I doubt it would happen but better safe than sorry though really there is not much stopping me from changing that resistor later

I like the idea of your arrangement though! I had thought about using a very white/milky straw as a tube for the LED's to sit in, to try to spread the light more even. I had heard that someone drilled into the rear of the backlight shield and hot glued LED's into that which sounded reasonable too!

[nightrnr]

I like the idea of your arrangement though! I had thought about using a very white/milky straw as a tube for the LED's to sit in, to try to spread the light more even. I had heard that someone drilled into the rear of the backlight shield and hot glued LED's into that which sounded reasonable too!

I might try that 2nd option some day, but in my experimenting, I didn't see an easy way to do that.

As for the straw, it may work, but...
I actually tried to re-use the florescent tube as housing for the LEDs (scary, I know, but I cut off the ends off with a dremel while outside with plenty of air and with very careful hands, lest I go mad).
It worked, sort of. It wasn't quite as bright as I wanted it though and seemed to dull the colors too much. But you never know until you try.
I had a lot more motivation for this mod back when I was all excited about it. I'm about out of my own ideas and am sticking with my 2 on each side implementation.
(actually did a 5-LED mod once for a guy once (one right in the middle), but was more trouble that it was worth and I was amazed that I even accomplished it; don't even ask me to explain that one either, I'm never doing it again ).

See my old sale thread for some other insights (and take my comments and findings with some salt, as I was still experimenting and forming my own opinions about it).

[Kouen Hasuki]

No worries mate, from what I see there seems to be no "best" way of doing it and just multiple methods