REPAIR GUIDE - TurboDuo: Sound Fix

[bishopcruz]

Ok, question

My Duo just came in, and CD audio is working great, but any Chip Audio/SFX is VERY low. The system was supposed to have a complete cap replacement, though I haven't looked inside to check. Is there something else that could be the problem? I checked it on both Turbochip games, like Legendary Axe and Bonk, and CD games like Gate of Thunder. In Bonk I'm only hearing like half of the music. In Axe, music SEEMS fine, but the sound effects are nearly non-existent. It's prettty weird overall.

I did have it region modded before it was sent out to me, but I assume that shouldn't be an issue.

[ClodBuster]

I had the same issue, mostly with digitized speech sounds. A FULL recap solved the problems. Some of the caps had seized really bad. Often you wouldn't see damage to the PCB underneath them until you removed the old caps.

[bishopcruz]

Problem is it was supposed to have been recapped already.

I found a youtube video with my exact same problem:


Just kinda sucks as I was really looking forward to this without having to worry about repairs on the caps.

Also if the PCB is damaged can it be fixed?

[Necromancer]

It's possible that something else could be the problem, but 99% of the time it's caps or cap related.  Even if it's been recapped, it usually ends up being a bad connection on a cap(s), unrepaired corrosion caused by leaking caps, or cap juice left on the board that's shorting something.

[bishopcruz]

It's possible that something else could be the problem, but 99% of the time it's caps or cap related.  Even if it's been recapped, it usually ends up being a bad connection on a cap(s), unrepaired corrosion caused by leaking caps, or cap juice left on the board that's shorting something.

OK.

Thankfully after I unplugged it, to see if my star screwdriver would work, (it didn't) I decided to plug her back in and check the headphone out to see if it was better.   So I plugged everything back in, and well, while the audio from the DIN still seems a little worse than out of the headphone jack, the problem I had before is gone for now. I'm no longer missing half of the sound effects like that video, and out of the headphones, it definitely seems better. I may just run the stereo out of that jack to the TV if need be. I have no idea why the sound would be working fine now, but not an hour or two ago. Really weird.

Other than that the thing is working great. Burns are working well, as is my copy of Ys 1 and 2, though I'm getting a bit of skipping (might need to have it resurfaced) now to test out CF2, Exile Ys 3 and Vasteel.

[javilevel]

Hello

First sorry for my english, I'm from Spain.

I have a TurboDuo, and I have the issue problem, the sfx sound works good, but de music CD don't work.

I don't have the time and the experience for repair my DUO, is there anyone in the forum who can do it for me for money?

Thanks.

[michichan]

So, I tried fixing my PCE Duo last year and eventually gave up, but after recent interest in it, I've tried again. A number of capacitors were replaced, but C616 lost one of its pads, and so I just couldn't get the sound to work. I replaced a few more and managed to get a solder that hits the edge of the lead for C616, but it's still scratchy sometimes and I'm afraid it's way to fragile. I want to run a lead wire to the contact point, but I can't figure out where it goes. There looks to be three different traces on this contact. Anybody know what I should be connecting to?

[grunthos]

 
I MUST SAY THANK YOU TO D-LITE & EVERYONE ELSE FOR THEIR EFFORTS
HERE. I RE-CAPPED MY TIRED TURBODUO AS NO-ONE ELSE IN THE UK
WOULD DO IT FOR ME ... IT NOT HAS 100% SOUND AGAIN. SO HAPPY!
I replaced all 6 caps in this photo. It wasn't easy for someone with my low
skill level, but if I can do it, anyone can. THANK YOU AGAIN.
 

 
THANK YOU ALL, THANK YOU ALL, THANK YOU ALL, THANK YOU ALL, THANK YOU ALL
 

[Keith Courage]

So, I tried fixing my PCE Duo last year and eventually gave up, but after recent interest in it, I've tried again. A number of capacitors were replaced, but C616 lost one of its pads, and so I just couldn't get the sound to work. I replaced a few more and managed to get a solder that hits the edge of the lead for C616, but it's still scratchy sometimes and I'm afraid it's way to fragile. I want to run a lead wire to the contact point, but I can't figure out where it goes. There looks to be three different traces on this contact. Anybody know what I should be connecting to?

Follow the traces from the pads. There should be a small via hole near them. You can push a wire or extra capacitor end through it and solder it where it needs to go.

[Zer0-2k11]

Hi everybody,

I'm in need of help. Sorry about the long post.

I got a PC engine duo on ebay that was described as "Working but no audio" about a month ago. When i received the Duo, first thing i did without testing it was i replaced all the caps with a cap kit i got from console5. After replacing all the caps, the audio was working. Then i proceeded to RGB mod it using the THS7314 method (8 Pin Din, Etc). Before doing the RGB mod it had CD drive issues so i ordered a new laser. After doing the RGB mod i decided to test my Street Fighter II HuCard i just received that day to see if everything was working alright and i noticed i had no sound again. So i looked around the audio circuit i noticed i had 3 caps backwards, C604, C614 and C678 (Audio circuit too) and i corrected them but still no sound. I also redid the 8 Din installation but again nothing . I also tried to clean around the audio circuit with some 99% IPA just in case if there was any cap residue that was shorting things outbut that didn't work out either. A day later after receiving a new HOP-M3, I manged to fix the CD drive back up again with a new laser and with a few pot adjustments (See my post in laser adjustment guide thread) and the CD drive is back up and running. So now i have 2 problems , one is the no audio problem and the other one is a ceramic capacitor at c518 has been damaged somehow. I don't know if it was like that before or if i did it. Would anybody have any ideas on how to fix the audio and 2, does anybody know the capacitor size and value?. I'm starting to think i damaged the 4558 because of the capacitors being backwards. If this is the case, would a RC4558 work as a replacement? (Texas Instruments 4558). Thank you everybody in advance for your time . 

[Keith Courage]

I would use a volt meter to find out where voltage is missing. Some traces go bad without any signs of visible damage. Also. make sure the main op amp is getting voltage. Very common for the op amp near the AV jack to have lack of voltage due to board corrosion damage somewhere.

[Zer0-2k11]

Ok i busted out the old multimeter and im getting a rating of 7.81 DC Volts on the Opamp when i place the positive probe onto Pin 8 and the negative probe to ground. I thought the opamp died so i replaced the op amp too as well with the RC4558 but still the same result. Is this normal voltage reading?

[Zer0-2k11]

Double post, please delete.

[Keith Courage]

What voltage are you getting off the positive lead for this cap? Circled in red far left. http://postimg.org/image/o1ci50n3z/

[Zer0-2k11]

Im getting 3.88 DCV