REPAIR GUIDE - TurboDuo: Sound Fix

gamereviewgod · 09/01/2011, 02:26 PM

Quote from: thesteve on 09/01/2011, 01:21 AMi move the 2 wires to the lower shield and resolder.
the top shield is soldered to the controller port and will need to be heated/unsoldered.
the system runs fine without it, but i reinstall it when done

Is it just an RF shield?

thesteve · 09/01/2011, 02:48 PM

yes its just an rf sheild

gamereviewgod · 09/05/2011, 10:06 PM

Just finished. The 22uf one sitting under the shield was A MESS. It has leaked everywhere. Took me 10 minutes just to see clear metal on the pad again. After all of that though, I have full stereo audio back, and I'm happy. Thanks again to everyone who has worked on this!

thesteve · 09/05/2011, 10:34 PM

your welcome

Bernie · 09/06/2011, 07:23 AM

This place is awesome. Its good we have the techs here that we do. I dont want to perform any kinda surgery on my systems.

Mystery · 12/02/2011, 11:19 AM

Hi guys

I recently got my hands on a PCE Duo which was supposed to be working, except for missing sound. I bought it and thought that a simple cap replacement would do the job.
After some online research I stumbled upon this awesome forum and after reading this thread, I was pretty sure that the system could be easily repaired.
When I opened it up, I saw that one of the previous owners already replaced quite a handful of caps around the 4558 amps. I got a little bit worried.

Long story short, I did a full cap replacement (finding a few additional leaky caps in the process), but unfortunately, the problem still persists.

I have full sound from HU card or CD (redbook audio, adpcm etc.), but it's almost inaudible, both on the AV out and the headphone jack.

What could be the cause of this?
I'm considering replacing the 4558 op amps. Could that work? Or does the current problem suggest a different approach/solution?

BlueBMW · 12/02/2011, 03:34 PM

If you have a meter... look up the data sheet for those 4558 op amps and check the power supply pin... we've had a few units where cap fluid causes the transistor that powers some of the audio chips to fail. Result is no / very low sound.

Mystery · 12/04/2011, 03:24 AM

Yes, I've got a meter. I checked all six 4558 amps and they all get power.

I made some progress, thanks to some very helpful PMs.

I got regular SFX and CD audio working on the headphones, by hooking the output of the upper 4558 (close to the AV port) amp to the L/R channels on the headphone jack. It's just a workaround and not really a fix, but for now it's working.

However, the ADPCM sound is still very faint. I can (barely) hear it, if nothing else plays, but that doesn't really do it for regular gameplay ;)
I put a wire from the M5205's pin10 to one of the 4558 input pins (not permanently, just for testing the ADPCM output) and I got crystal clear sound from it. However, just on one channel, and adding a trace to the other input pin screws the whole sound up.

thesteve · 12/04/2011, 07:32 PM

2 points
1. adpcm is 1 channel.
2. it sounds like you losing it around the AVC.

the avc is voltage controlled, the last one i did wasnt getting the control voltage to it due to a bad via

Mystery · 12/05/2011, 02:36 PM

Quote from: thesteve on 12/04/2011, 07:32 PM2 points
1. adpcm is 1 channel.

I know. Perhaps I didn't phrase my attempt to get it working correctly.
I was just stating, that when I put the ADPCM to one of the AV amp inputs, it came out crystal clear, but when I put the same output from the ADPCM pin10 to the other AV amp input at the same time, the whole sound got messed up.
I'm aware that it's not stereo, but I still have to get the signal on both channels somehow

Quote2. it sounds like you losing it around the AVC.
the avc is voltage controlled, the last one i did wasnt getting the control voltage to it due to a bad via

Anything I can do to test that theory and if necessary fix it?

thesteve · 12/05/2011, 05:09 PM

i dont have the data sheet in front of me for the AVC (the ZIP chip by the heatsinks) but i traced the sound to its inputs, with nothing out.
checked the voltages on the control pins per the data sheet.

SNKNostalgia · 12/22/2011, 12:51 AM

Sighhhh, my US Duo's right sound channel is quiet. I didn't even touch the system in like 3 months. It worked fine last time I played it. At least I can play it in mono (left) sound for now. I need to get another 3.5mm to RCA cable and use it with headphone output to make sure it is just the AV out or the stock Duo AV cable. Fun, fun, fun!!! Man US Duo's suck ass!!! Seriously though, up there with RROD on Xbox 360s... hell probably worse.

BlueBMW · 12/22/2011, 08:00 AM

Nahh... Duos arent worse than RROD. We can fix them without expensive crazy reball equipment! And, it did take some 20 years for them to fail, not 1 or 2 like those silly xboxes.

Nazi NecroPhile · 12/22/2011, 09:47 AM

Quote from: SNKNostalgia on 12/22/2011, 12:51 AMMan US Duo's suck ass!!! Seriously though, up there with RROD on Xbox 360s... hell probably worse.

Dried out caps after twenty years equals sucks ass?

SNKNostalgia · 12/22/2011, 05:20 PM

Actually, I heard of a lot of Duo systems sound going out 10 years ago. So I am going to more than assume this has been going on for a while now.

Nazi NecroPhile · 12/22/2011, 05:53 PM

Quote from: SNKNostalgia on 12/22/2011, 05:20 PMActually, I heard of a lot of Duo systems sound going out 10 years ago. So I am going to more than assume this has been going on for a while now.

Of course some failed ten years ago but not all of 'em or even a majority. How many first run 360s do you think will be alive in 2015 without help? I'd say 10% would be generous.

SNKNostalgia · 12/23/2011, 05:35 AM

In the long run they will end up the same. The Duo CD drive isn't all to reliable as well. I had to replace the lens once without even playing scratched up game discs or CD-Rs. I ended up buying 4 replacements and tried out a few CD-Rs burned using the best media/method possible, since I felt like I had nothing to lose with the replacement lenses in stock.

Yes, all 360 first designs have roughly a 90% failure rate in the long run. I seriously doubt years from now a first working model 360 will run you up that much cash though. We have to at least admit that the black Duo models are a huge risk in longevity.

The point I am making is that black Duo systems have a serious flaw (flaws actually)... yet it is the best looking design and the most sought out. It is just a shame. Almost everyone I know of that has a Duo has had this problem. Overall the 360 is worse on failure rate, but at least they won't be $400+ for a working model 20 years later.

BlueBMW · 12/23/2011, 08:11 AM

Interestingly, the original Duos have a higher quality PCB than the later Duo R models. The design seems sound, just cripples by defective caps.

ApolloBoy · 02/05/2012, 02:14 PM

Quote from: BlueBMW on 12/23/2011, 08:11 AMInterestingly, the original Duos have a higher quality PCB than the later Duo R models. The design seems sound, just cripples by defective caps.

I've been replacing some caps on a Duo for someone and I was genuinely surprised at how durable the board was, especially compared to the TE which has a shitty PCB. Kinda makes me wish I didn't get rid of my region modded PCE Duo. And on the subject of the Duo-R, has anyone had to replace the caps on that yet?

BlueBMW · 02/05/2012, 02:16 PM

Havent seen caps go out on the Duo-R/RX yet, but I have now seen a PC-FX with cap issues...

esteban · 02/07/2012, 12:50 PM

Quote from: BlueBMW on 02/05/2012, 02:16 PMHavent seen caps go out on the Duo-R/RX yet, but I have now seen a PC-FX with cap issues...

Say it ain't so!

Damn it.

How about caps on SuperCD unit? I know it isn't as popular, but what is your take on that bit of hardware?

SNKNostalgia · 02/07/2012, 05:10 PM

I still need to see if my Duo right sound channel is quiet due to the AV cable maybe. I already replaced the main upper left sound caps when the CD audio went quiet.

The thing that pissed me off the most is that I bought my Duo new from TZD back in 2000-01 and barely plugged it in and played it for like 5-6 years. Then I played it for 1 year straight 2007 with reasonable gaming sessions and the caps went out for the first time... not to mention the lens went out and I bought 4 replacements which was an easy fix. Then I let up on playing it again the past 2 years and the right sound channel is going out due to another cap problem or possibly the AV cable I hope.

Oh well, at least it should be an easy fix if it's the caps. I guess I can just use the headphone output converted to RCA for now till it gets fixed, lol.

BlueBMW · 02/08/2012, 12:15 AM

Quote from: esteban on 02/07/2012, 12:50 PM
Quote from: BlueBMW on 02/05/2012, 02:16 PMHavent seen caps go out on the Duo-R/RX yet, but I have now seen a PC-FX with cap issues...
Say it ain't so!
Damn it.
How about caps on SuperCD unit? I know it isn't as popular, but what is your take on that bit of hardware?

I've seen several SuperCDROM2 units with cap issues

Hopefully DuoR and RX systems arent next! They dont have the SMT Aluminum caps like the others though... Even the leaded caps will eventually dry out, but at least they dont tend to leak all over the board and destroy stuff.

Sorry to bring bad news

Hopefully I'll have some FX cap charts up soon.

Quote from: SNKNostalgia on 02/07/2012, 05:10 PMI still need to see if my Duo right sound channel is quiet due to the AV cable maybe. I already replaced the main upper left sound caps when the CD audio went quiet.

The thing that pissed me off the most is that I bought my Duo new from TZD back in 2000-01 and barely plugged it in and played it for like 5-6 years. Then I played it for 1 year straight 2007 with reasonable gaming sessions and the caps went out for the first time... not to mention the lens went out and I bought 4 replacements which was an easy fix. Then I let up on playing it again the past 2 years and the right sound channel is going out due to another cap problem or possibly the AV cable I hope.

Oh well, at least it should be an easy fix if it's the caps. I guess I can just use the headphone output converted to RCA for now till it gets fixed, lol.

Might as well just go ahead and have all the rest of the caps done. I've had some systems not read CDs and then after a full cap change start working again. So I know the caps will eventually affect more than just the audio output.

KingofGames · 02/13/2012, 10:31 PM

I'm going through the process of reading through this topic, but in the meantime, I figured I'd bring up my scenario. I recently acquired a Turbo Duo. I was told the unit did not power up, but upon receiving it, I had no problem powering it on. The Turbo Grafx portion works perfectly. The CD portion loads discs fine, plays the basic audio properly, but struggles with the CD-based audio. I was able to load up a JP version of Y's III (is this typical? I've not modded the system myself). At one point, the CD audio kicked in, but quickly died out. Through the headphone jack, the audio can be heard very faintly, though there is a hissing noise as well. Does this sound like a cap issue? I'd like to get an idea before going through the trouble of replacing anything. Thanks for any assistance!

thesteve · 02/13/2012, 10:34 PM

thats common.
its typically cap related.
caps and cap fluid corrosion.
its fixable

KingofGames · 02/14/2012, 01:07 AM

Yup! I replaced the two 22uf caps tonight with the help of a friend. Man, it was harder than I thought! However, I now have CD audio! Amazing to see that this thread has serviced so many people over the past 6 years.

ogre · 03/02/2012, 06:53 AM

I recently got my old dead black duo working. It was out if commission for over 2 years. It ended up being just a dead power brick and the one from retro game cave got it running. Now after two years of not running the sound is completely gone, as well as my saves.

A year before it died the CD sound went and I changed the caps above the heat sinks and that fixed it. Does anyone know of what caps are related to all audio, hucard and CD.It has virtually no sound unless I turn the volume to the max, and even still it sounds faint and scratchy.

BlueBMW · 03/02/2012, 07:48 AM

The consensus these days seems to be that ALL the capacitors should be changed. Also make sure that when changing caps that you clean all the leaked fluid and corrosion. I know its a pain, but for the long term reliability of your system, this must be done.

ogre · 03/02/2012, 10:43 AM

Ugh, I guess I kind of figured that is what needs to be done. I was just curious as to which ones specifically controlled the audio as I changed some already, and wanted to make sure those still are not suspect(Defective). Any good techniques for not lifting the solder pads? When I changed the one (10uf) located under the HU-Card slot I accidentally lifted the pad. The soldering is the easy part, it is the removing of these little bastards that sucks.

bust3dstr8 · 03/02/2012, 11:06 AM

Use two irons and a drop of paste flux. Heat both sides and push the cap off the pads. Then use a fluxed wick to clean.

Something like this works good for getting in tight places.

meka · 03/13/2012, 02:03 PM

I have the exact same problem with my Super CDROM2

BlueBMW · 03/13/2012, 11:46 PM

Quote from: meka on 03/13/2012, 02:03 PMI have the exact same problem with my Super CDROM2

Then step on over here and start changing your caps!

https://www.pcengine-fx.com/forums/index.php?topic=9544.0

meka · 03/17/2012, 08:52 AM

Just replaced all the caps on the Super CDROM2 and it works great, thanks for showing me the post and to the person who posted it, it really helped.

ogre · 03/19/2012, 03:54 PM

I finally got around to changing all the caps on my resurrected black pc-engine duo. Before I had no sound whatsoever , and now the only sound I have is crystal clear loud redbook audio. I have no hucard sound, and the only other sound I can hear is in lords of thunder when the character gets hit or dies. The system has no other issues and loads any game perfectly(Actually quicker than my Duo-R). All the caps are new, and as far as I can tell are working. Does anyone now what chip regulates the hucard audio?

thesteve · 03/19/2012, 05:07 PM

the hucard audio is not regulated
its mixed after the AVC chip (the ic behind the heatsinks with pins on one side only)

ogre · 03/19/2012, 07:27 PM

Is that the chip amplifies the audio that the hudson chip outputs? I am only guessing this may be the problem as redbook audio works, as does some of the voices in Fatal Fury Special. It does sound like it is trying to produce sound, but only faintly. This just frustrates me as before the power brick broke it was working perfectly.

thesteve · 03/19/2012, 09:43 PM

no that chip lowers the cd audio before mixing in the Hudson chip.
the Hudson chip is not dealt with separately at all

ogre · 03/19/2012, 10:48 PM

Ok, so I guess I will just have to trace the audio from the HU6280. I am definitely no expert, but all info points to that producing the audio. The chip obviously must be working as it is also the main CPU. If no chip amplifies the PSG coming out of this does it go through any filtering caps?

thesteve · 03/19/2012, 10:55 PM

thesteve · 03/19/2012, 10:58 PM

thanx to charlie for the schematic

ogre · 03/19/2012, 11:15 PM

Thanks. Now I will have to do some digging.

notsonic · 04/29/2012, 07:27 PM

just want to add some more to this thread and see if anyone has any suggestions.

the original condition of my duo was low sound. i do not know if it got better or worse after being on for a while as i didn't test that.

i replaced the two post amp caps with 10uF 35v caps from radioshack. sound levels were back to normal. sound quality was maybe a little shitty/peaky sounding but that could just be how it is, i forget. cd audio was perfectly clear. i left it on for a few hours and it started popping, both through the av out and the headphone jack.

I'm going to go and replace the pre amp ones and the other caps people have mentioned to see if that helps. none of the caps look physically bad, though they are so small its entirely possible theyve leaked and its not 100% obvious.

also, does anyone have any tips for removing these kinds of caps?

thesteve · 04/29/2012, 07:47 PM

press them against the board and twist back and forth

ApolloBoy · 04/29/2012, 07:49 PM

Quote from: thesteve on 04/29/2012, 07:47 PMpress them against the board and twist back and forth

This is the technique I use as well. Gets them out every time and there's no damage to the board this way. Sometimes you'll even pull the old cap legs right off the pads which makes things easier!

Jugbug · 05/10/2012, 11:37 PM

I'm new as a poster around here, but have been reading up for awhile. I just wanted to give a big thanks to this thread I was able to restore my Duo's audio. It was having issues for a long time and then was finally silent. I plan on doing a total capacitor replacement when I've got some time. Any advice from people who have done this is welcome. My main concern is if I go radial if there's enough room under the shield, or if I go SMD if the caps will be too large for the pads. Thanks again, and here's hoping my Duo at least lives longer than I do

Edit: Thanks for the advice, BlueBMW.

BlueBMW · 05/11/2012, 01:46 AM

Theres usually plenty of room to use radials under the rf shield. Just bend then over after install.

thesteve · 05/14/2012, 12:09 PM

the ceramic SMD size 1206 caps fit the pads perfect

ApolloBoy · 05/22/2012, 02:36 PM

I just use normal leaded caps, way easier to solder in than SMD caps.

Jugbug · 05/24/2012, 09:54 PM

Thanks for all the input. I hadn't even considered ceramic SMDs. I'll probably go with radials for the ease. Bet those ceramic SMDs make for a nice looking install though...

thesteve · 05/25/2012, 12:04 PM

the ceramics are easier too

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REPAIR GUIDE - TurboDuo: Sound Fix