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NEC PC-Engine/SuperGrafx => PC Engine/SuperGrafx Discussion => Topic started by: choijimmy on December 25, 2012, 05:35:02 AM

Title: PC Engine GT Sound issue
Post by: choijimmy on December 25, 2012, 05:35:02 AM
Hi,

  Merry X'mas!

  I recently got PC Engine GT with No sound. Replaced the capacities by a retro game shop. After fixing, the sound come back but with two questions

1) I found that even I put my head phone into the jack, I got sound from Both  a) head phone  b) the PC Engine GT speaker .  Is this normal? I think if I put the head phone in, the GT speaker should be in mute, am I right?

2) If I turn the volume to quite large ( around 60% ), yes, the sounds is so loud but I heard some static ( like sound with electromagnetic interference ), is it normal?

Thanks a lot!
Jimmy
Title: Re: PC Engine GT Sound issue
Post by: turbokon on December 25, 2012, 06:25:28 AM
It's probably because the pin that makes contact to enable sound thru speaker when no jack is plug in is broken. So they just jump the contact points. I've done this before.
Title: Re: PC Engine GT Sound issue
Post by: choijimmy on December 25, 2012, 11:14:25 AM
It's probably because the pin that makes contact to enable sound thru speaker when no jack is plug in is broken. So they just jump the contact points. I've done this before.

Thanks a lot!

Any idea for the static when volume is medium to large? I think this is abnormal too.

thanks again
Jimmy
Title: Re: PC Engine GT Sound issue
Post by: BlueBMW on December 25, 2012, 01:33:35 PM
I'd guess that when the caps were done, there was some cap fluid not fully cleaned up still causing some minor shorting and static.
Title: Re: PC Engine GT Sound issue
Post by: choijimmy on December 25, 2012, 03:52:52 PM
I'd guess that when the caps were done, there was some cap fluid not fully cleaned up still causing some minor shorting and static.
I'd guess that when the caps were done, there was some cap fluid not fully cleaned up still causing some minor shorting and static.

Thanks a lot! Talked to that guy who fixed my GT. He said indeed the GT volume shouldn't be that loud, he made the sound so loud and that's why there is static when I turn the volume to medium to high. I think he is right, I feel the sound is much louder than usual when I turn the volume to high :)
Title: Re: PC Engine GT Sound issue
Post by: choijimmy on December 25, 2012, 03:55:47 PM
It's probably because the pin that makes contact to enable sound thru speaker when no jack is plug in is broken. So they just jump the contact points. I've done this before.

Talked to that guy. He said due to erosion the GT board, he can't trace the circuit anymore. Thus, he jump the contact from the IC audio output to GT speaker. Thus, GT speaker alway on even though ear phone is pluged

Thanks!
Jimmy
Title: Re: PC Engine GT Sound issue
Post by: thesteve on December 26, 2012, 07:57:32 AM
the circuit is simple enough, if you ever want it fixed right
Title: Re: PC Engine GT Sound issue
Post by: choijimmy on December 26, 2012, 01:17:04 PM
the circuit is simple enough, if you ever want it fixed right

however it GT, there are some plastic stuff (like bubblegum) on top of the circuit, it makes the circuit hard to trace... according to that guy.
Title: Re: PC Engine GT Sound issue
Post by: thesteve on December 27, 2012, 06:54:35 PM
its RTV, and not too tough to trace around.
besides, if your headphones are right, it just goes to the speaker from there