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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: pooyan on August 21, 2008, 02:48:11 AM

Title: No sound issue when using the headphone out of a PCE Duo
Post by: pooyan on August 21, 2008, 02:48:11 AM
Lately I have some serious problems with the sound of my PCE Duo (stutters, crackling sounds, no music, etc). After reading some posts on this forum I learned that this is a very well known problem and has something to do with dried out caps or so. the solution would be to replace the caps (although no 100% guarantee).

However, today I hooked up a PC speaker system (5.1) to the headphone out and the sound quality is amazing, better than ever before. So, why is the sound when it comes from the A/V output so bad, while when I redirect it through the headphone out it's very good?

Anyway, now I don't feel the need anymore to renew electronic parts.  8)
Title: Re: No sound issue when using the headphone out of a PCE Duo
Post by: nat on August 21, 2008, 04:25:05 AM
The headphone jack uses a seperate amp circuit from that of the A/V port. The bad caps in your particular Duo must be isolated to the post-op amp circuit for the A/V port only. Once the pre-amp caps go and/or the caps in the headphone jack circuit, you'll lose sound over the jack as well. It's only a matter of time. Not to sound grim or anything.
Title: Re: No sound issue when using the headphone out of a PCE Duo
Post by: pooyan on August 21, 2008, 04:49:49 AM
Quote from: nat on August 21, 2008, 04:25:05 AM
The headphone jack uses a seperate amp circuit from that of the A/V port. The bad caps in your particular Duo must be isolated to the post-op amp circuit for the A/V port only. Once the pre-amp caps go and/or the caps in the headphone jack circuit, you'll lose sound over the jack as well. It's only a matter of time. Not to sound grim or anything.

Thanks for the info. OK, so I will do a bit more reading about changing caps (my technical skills are pretty low profile), and when the time is there (no sound any longer from the headphone jack) perform some surgery on my PCE.
Title: Re: No sound issue when using the headphone out of a PCE Duo
Post by: Duo_R on September 09, 2008, 09:01:50 PM
I have replaced about 75% of the caps, huge improvement. I did more that just the pre/post amp circuit. I am probably just going to do the whole thing because with each cap it is a ticking time bomb (With the exception of the large radial caps). I got the technique down for removing the SMD caps.