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View topic - Sound Board Component Difference, VA1 837-9024 VS 837-7719-01

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  • Joined: 29 Apr 2021
  • Posts: 2
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Sound Board Component Difference, VA1 837-9024 VS 837-7719-01
Post Posted: Thu Apr 29, 2021 7:43 pm
Hello all,

I'm new. I've recently gotten into recapping Game Gears because I really like them and would like to learn how to repair and put them back into circulation.

I have two GGs that need to be serviced. I noticed a difference on the soundboard of GG version 837-7719-01 (Made in the USA). There's a component on the board that looks soldered on by hand as opposed to by a machine. I'm not sure what the purpose of the component is. Could someone please help me identify the name of the component, its purpose, and also please let me know if the component on GG 837-7719-01 is in fact aftermarket?

GG VA1 837-9024's component in question seems to be OEM.

Two pics are attached for comparison.

Thanks!
837-7719-01.jpg (4.73 MB)
837-7719-01.jpg
VA1 837-9024.jpg (4.57 MB)
VA1 837-9024.jpg

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  • Joined: 24 Mar 2021
  • Posts: 50
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Post Posted: Thu Apr 29, 2021 7:57 pm
That's a "common-mode choke"

Like this one: https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/744253200/65649...

Its purpose is to prevent the audio amplifier from becoming an accidental radio receiver.

I can't help with authenticity, however.
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  • Joined: 29 Apr 2021
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Post Posted: Thu Apr 29, 2021 8:24 pm
I see, great! Thanks for helping identify what that is. I'm learning about common-mode chokes now. Right, they're to filter and reduce noise.

Would you happen to know whether the component on VA1 837-9024's soundboard serves the same purpose?
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  • Joined: 24 Mar 2021
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Post Posted: Thu Apr 29, 2021 8:27 pm
I don't know for certain, but it seems extremely likely that it is the same, just fully encased in epoxy.
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  • Joined: 04 May 2021
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Post Posted: Tue May 04, 2021 11:35 am
GGNoob wrote
I see, great! Thanks for helping identify what that is. I'm learning about common-mode chokes now. Right, they're to filter and reduce noise.

Would you happen to know whether the component on VA1 837-9024's soundboard serves the same purpose?


SEGA used 3 different types of CMC. manufactured by Tokin (on your 837-7719 board) and Taiyo (on your 837-9024 board). If you open a few more Game Gears you will also find Tokin one that has the coil covered.

The CMC is only in the headphone circuit and in a lot of Japanese GameGears it is simply bridged.

If needed, I have NOS Tokin CM04RC02T coils laying around.
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  • Joined: 05 Nov 2014
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  • Location: Auckland - NZ
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Post Posted: Mon May 10, 2021 12:18 am
I was digging through some game gears yesterday and found several variations of the choke. The differences being in the size of the plastic base they are mounted on and the addition of silicon to stop it rattling around. One board was a bit different and had none at all by design. I have attached a picture for reference.
20210509_155914.jpg (582.65 KB)
20210509_155914.jpg

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