Author Topic: PC Engine GT - Speaker audio good but... Weaker than it used to be.  (Read 156 times)


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Hi all,

My Pc Engine GT has a very long story.
It was recapped the first time by someone that produced a fair amount of damage to its motherboard but in the end "made it work".
After that many years passed and I've sent it to another modder to get RGBDRV mod. The result is frankly stunning.
The modder also suggested a full recap because of the not great job done previously (gorilla glue, pads ruined, etc).
In the end my Pc Engine is now working fine with a marvelous screen but the audio compartment is not as flawless and powerful as it used to be.

In earbuds I hear a hum, it could be related to RGBDRV mod.
If someone has a suggestion it would be great but it is something I can live with (using earbuds with a volume potentiometer makes it a LOT better).
The main problem is using the unit with its speaker...
Volume sounds...
A bit lower.
It is not super low but I remember my PC Engine shouting with marvelous bass and now it is just...
Loud but...
Decent, not great.

Am I dreaming or not?

I've read in the forum that some modders put 47uf capacitors for audio instead of the designed 33uf so it could be that maybe the 1st modder used the 47uf and the second put 33uf so I hear all this difference?
How can I test if everything is how it should be?

If I want to test functionality with 47uf I need to remove the current 33uf or I can put them connected together (or add a 14uf to the 33uf)?

Please forgive my ignorance and thanks for your time and help.


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Re: PC Engine GT - Speaker audio good but... Weaker than it used to be.
« Reply #1 on: July 08, 2021, 06:40:50 PM »
Hi all,

Tonight I opened the unit and took some pictures about the current status, maybe someone can point out potential issues:

Thanks :)

Keith Courage

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Re: PC Engine GT - Speaker audio good but... Weaker than it used to be.
« Reply #2 on: July 12, 2021, 08:09:23 AM »
I can't notice anything from the pics but your problem is either 1 of two things.

Either there is a bad trace for 1 of the 4 caps just behind the headphone port(2 100uf and 2 33uf)

or, the internals of your heaphone port have been damaged from being heated too much during the cap change. Years ago when I recapped my first Turbo Express I did that very thing. Had to replace the headphone port.