REPAIR GUIDE - TurboDuo: Sound Fix

[agt_dale_cooper]

OK, success!  Caps finally showed up today from Parts Express, so I went to town on the thing.  First pull:  22uF, 16V at C323.  Result:  no audio love.  In looking to pull the next victim, noticed that there was an important difference between all the pics and my board:  C615 was MISSING!  (Duh, first rule of TG16 repair, insure all the shit is THERE!!!  Cap did NOT fall out when I opened it like reply 83, though, so it didn't occur to me to look..)  So, off I went to my bag-o-caps, only to discover that the 47uF, 16V was NOT a size I ordered.  Soooo, I threw in a 100uF, and lo and behold, some audio showed up, albeit very faint.  Encouraged, I replaced C604, C610, C614 and C613 as original post suggests, and WHAM! out rolls some nice Lords Of Thunder!!!  Woohoo!!!
Questions for anybody:  I've heard different types of audio terms being bandied about:  ADPCM, Redbook, etc....how do they all pertain here?  Is PCM generated by the game code / Redbook is pulled off CD?  Haven't I heard a third term used?
Haven't seen any ill effects from using the 100 as opposed to the 47....anybody tracing these circuits?  Are we gonna end up with LOUDER audio like Agt. Nat did using 47uF caps instead of 33uF caps in his TG16 Express audio fix?  Thoughts, anyone?  [Doesn't sound any different than my working USA Duo, but I suppose it's possible....may try altering the post op amps with higher uF units]
Methodology used:
1)  Pull caps using needlenose and back-and-forth rocking motion.  Don't really pull, you don't want to lift the pads these things are sitting on...just trying to snap the existing joint.  Also, there are fuses attached to the bottom of the board at these points, don't really want to use excess heat.
2)  Buy caps from Parts Express.  Pray that USPS delivers them quicker than they did mine.  Thanks again PCEH for a great supplier...much easier to look through than Mouser or Digi-Key, IMO.  Pictures are worth their weight in gold when replacing stuff.
3)  Prep pads by tinning, using flux pen beforehand if you've got one.
4)  Bend leads of caps into ][ style shape, where top is inside cap, length of vertical = length of horizontal foot.
5)  Tin ends of caps
6)  Use tweezers to hold cap in rough position, use end of soldering iron to link tinning on pads to tinning on caps.  If well tinned, should flow right together.

Bottom line, seems replacing C615 fixed the #1 case, no audio, as I'd only replaced C301, C616 and C323 before realizing C615 was missing, and got no audio out of replacing those three.  Got no audio?  Why not start with C615?  Perhaps this can act as a sight on the 'shotgun'....hee.

[Still waiting for Liar smiley #2 to be replaced by Hot Coffee Drinking Smiley...]
agt_dale_cooper

[Duo_R]

I would replace the 100 with a 47 although it shouldn't hurt. Just based ont the fact that the Turbo designers chose that cap for a reason. 47's aren't uncommon at all. Just pony up at RatShack, they always have that size (unless you have a reason to make another online order).

[agt_dale_cooper]

RRRRR....lost sound again, right back to where I started (CD sound is VERY VERY faint).  Gonna pull C615, replace with 47uF instead of the 100uF, HOPE that this 100uF has freaked out it's neighbors and they don't want to work anymore.  Will pull/replace all previously installed audio-related caps, hoping again that somebody has blown...makes a bit of sense, really, but I think I'm grasping at straws...we'll see, will post findings.

[agt_dale_cooper]

Wow, nothing.  Pulled all previously installed per Nat's suggestion (I too enjoy the notion of a clean slate...), reinstalled all to no avail.  Did the 47s up by the LED, did the 47 that somebody said isn't part of the audio circuit, C312.  Ran the thing with the top off, used eraser at end of pencil to manually shake all installed caps to test for crappy joints (in theory, this should sound porpoise up and down if you've got a crappy joint, right?)  Audio is there, it's just painfully faint.  HuCards work fine, in game button mashing sounds are there as well, it's just the CD audio.

Nat, where is this mystery capacitor mentioned a couple times by Erik and I?  Could this be my issue?  I was supposed to ship this thing today after installing region switch, and as luck would have it, audio has disappeared.....frigging switch install was easier than sorting this &^%^%$ audio issue!!!!!!  HAHAHA!!!

On a humorous note, the timestamp on my mod of that switch document says 04-19-03....been a while since I've done that mod, but it still works famously... (and yes, Twin Peaks STILL rules!)  For whatever it's worth, that document is directly applicable to the JAPANESE consoles, as the pins are simply a mirror image of one another...[not sure whether this Pin 29 business is required or not, but I did it anyway....reminded me of the PSX days...]

Anybody know how to test caps in the circuit / while the thing is powered?  A brief outline, if anybody does, might be helpful....gonna Google, see what it says, I've had it up to HERE with this (*&&^% audio issue.  I WILL fix this thing.

[agt_dale_cooper]

Wow, have spent literally ALL DAY trying to repair this thing.  Here's what I tried:
1)  switched lasers between my US and Jap units.  No dice, wouldn't read the CD, as wiring in middle connection isn't the same between the two, didn't feel like pulling and rewiring the pins.
2)  Pulled/installed fresh/tested caps all day, testing for both Redbook (CD Audio) and ADPCM (system generated snippets like the voice in Gate Of Thunder (J) ).  Installed fresh caps in all spots but:  C961, 962 (near power switch), C512, 515, 517, 519, 523 (above and near HuCard slot), C105, 110, 122, 133, 164, 200, 201, 202 (in between CDROM unit and front of machine).  All other caps I replaced, tested with GOT, got nowhere except severely irritated with the loud buzzing where the voice in GOT is supposed to be.  Sort of like having the buzzer from Family Feud go off like 3000 times today...
3)  Discovered that Pin 29 grounding for Japanese switch install is indeed required.  WSOD without it when trying to play USA games.  [tried pulling this, as it was the only thing that had electrically changed since I got the thing to play audio the other day....]

Now I'm literally out of caps, gonna get some more from PE...this project is HUNG for a couple of days while they're in transit, then.....urgh.

Next project is prolly gonna be to tear down my fully working USA Duo cap by cap, try to isolate what caps are responsible for which audio...pull cap, test, record comments, continue...that'll be fun too.

[blueraven]

  Crap. Well, the sound in my duo just went totally dead. It looks like i'll be posting my own follow up here in the near future.

[MarsPants]

Hey, it's me again! I started to replace the capacitors and I just finish replacing both the post amp. When I hooked everything back up the sound worked longer then usual but eventually went out. Also now the cd drive doesn't spin  . I was wondering if there is anything I could have done that would have caused this? The laser does move but the CD just does not spin. Any ideas would be great.

Okay never mind! I fiddled with the wires leading into the CD drive and it works again! It was a silly mistake I suppose.
However, any ideas what caps I should replace after the post amp? I'm assuming the pre amp so I think I'm going to try it now.

[Duo_R]

I went crazy after replacing all the post/pre amp caps and having sound but issue with intermittent static and sound volume issues (it was the shotgun approach). Nat predicted leaking cap fluid causing the issue and suggested a dishwash. I did the dishwash (you can get details on how I did it on another post) and after NO static issues. What was strange was initially my sound didn't come after the dishwash, but then after a few tests (it went in and out) it came on and never went out again. I did notice a 40% drop is sound output. It isn't a huge issue, but I have to turn the volume WAY up. I think I have a bad cap on there somewhere. If I were to do all over again here is what I would do with a  Duo with sound issues:


* Remove all the caps in the pre/post amp area (find the diagram on this website)
* Dishwash with the 7th generation soap Nat suggested - 1 cycle with soap, 2 cycles with warm/hot water (AND NO HEAT DRY, AIR DRY ONLY)
* Replace with new caps in the pre/post amp area

Why do I recommend this? Because some of the caps leaked and will limit wash/rinse underneath. Removing them ensures a 100% clean and you don't also run your brand new caps in the wash. I think it also helps the board dry faster. The way I did it was remove/replace caps then wash, but again I would do it in the order I listed above in the future. I just spent too much time monkeying around with the cap replacements, and I replaced all the caps thinking it was another issue before finding out about the dishwash method Nat suggested.

It was nice to fix the issue (but I need to get another cap replaced to get sound loud again), I debated on changing my username to DishwashDuo, but the Duo_R I purchased justified keeping that tag.

[agt_dale_cooper]

I learned something about capacitors today....
If your multimeter has a 'Diode Testing' function (symbol looks like ->|- on my Harbor Freight special), try this for testing caps in the circuit:
1)  Locate the Diode Testing function, switch to it.
2)  For post-op and pre-op caps (I'm using C604 as example here):  connect the positive lead of the MM to the positive side of the cap, connect the negative lead of the MM to the negative side of the cap, HOLD IN PLACE for like 30 seconds.  Readout will say "1", but hold in place for 30 seconds.
3)  Remove leads, switch MM to DCV = 20.
4)  Connect + lead to + cap, - lead to - cap
5)  Should observe values DECLINING...mine started at .35 for C604, declined as long as I held leads in place.

What's happening here is that the Diode Testing mode is actually supplying a small amount of charge to the capacitor, which it (if functional) absorbs....switching the MM to DCV = 20 (I selected 20 because it is closest to the 16V rating of the cap) and connecting actually allows the cap to DISCHARGE while you're measuring it!  Different caps on the board behave differently, but all the ones in the audio circuit appear to exhibit the same behavioral pattern.

This can be used to tell whether or not your caps are trashed, I think....might actually be used as a means of 'jump starting' caps as well....

Anybody that actually knows something about MM use / any non-layman-like-me type with useful knowledge have commentary?  [I'm reading while futzing about with my multimeter, DETERMINED to solve this audio issue.....I'm currently testing my working USA unit against non-working JAP unit, learning odd things along the way.  I think we've blown a resistor / fuse somewhere in the audio circuit, and I'm determined to find out WTF the bottom line is....]

Forgive me if you think I'm talking out of my ass, electricians, but this might help somebody....

[MarsPants]

Ahhh! It works  After a REALLY bad soldering job and about an hour trying to fix a huge blob of goo It works by some divine magic. All I did was replace the Pre and post amp and it did it for me. I can't say I'm completely in the clear yet because it seems that people post having problems after the fix. I usually could only play for about 2 minutes before sound malfunction, but I was just playing for about 30 minutes and no problem at all. Anyway, good times! This form rocks

[agt_dale_cooper]

Well, the PCE Duo hit the dishwasher this afternoon (went to Grandma's, made Chinese for dinner, threw the thing in while we were wrapping potstickers), it came out looking like reverse-engineered ass.  White funk all over the board, just like others have mentioned.  Bought some rubbing alcohol on the way home, hit it hard with the toothbrush, but even this leaves a white haze behind....

Question:  Is this haze harmful?  I doubt it (as it's no doubt non-conductive), but I need to throw it out there...

I'm gonna hit it again tomorrow (Black Friday ads look like reverse-engineered ass as well (but, CircusTitties have Arcade 360s with free refurbed 20GB HDD + wireless controllers for $199???  If these have Jaspers in them (with new onboard RAM), this may be a steal!  Pay close attention, though, if your local CT is slated for going under, they may not have all deals....these stores have actually been sold to a liquidation entity), retailers are gonna FLAIL with the economy in the state it's in) with the alcohol, then give it a good once over with the air compressor to speed the drying process...if my caps show up (again 'Parts Express' seems to be a misnomer.....nice folks, really (I called them the other day trying to replace C509 [which I believe to be the Tennokoe functionality], guy was super nice, even schooled me a bit!), but the shipping time SUCKS), I'll start soldering them on.  Yes, FUN FUN FUN, but it'll be better than being in with the maddening crowds at WallyWorld...

End of yet another exercise in insuring parentheses have been properly opened and closed/a post that looks like an Excel formula....heh.  More news to follow...enjoy your Friday, if you do that sort of thing....[throw an elbow or two for me  ]

[Duo_R]

AGT Dale,

I had some white haze stuck to the parts of the board that had excessive goo stuck to it. Did you run 2 washes with water only? Run 2 cycles water only (warm/hot water) with Air Dry. Then use mixture of 50/50 of rubbing alcohol / water with toothbrush on the board. That should remove most of the haze. It should look really clean after that. But mine was as yours was described. Then the most important piece is letting it dry for at least a couple of days. Setup the board in front of a box fan in your garage and just let the sucker dry out REALLY good. You don't want to risk something shorting out.

[agt_dale_cooper]

Well, got the thing back together after it's hot date with the dishwasher...

CD audio did NOT return, although ADPCM did (!!).  CD audio is still REALLY faint.  This rules out the M5205 (which I did find on eBay, BTW:  http://cgi.ebay.com/NEW-ICS-M5205-OKI-18-PINS-DIP-5205_W0QQitemZ150117198253QQcmdZViewItemQQptZBI_Electronic_Components?_trksid=p3286.m20.l1116 )

I had to pull it apart again to fix the power switch (seized up after I didn't dry it after removing from DW..), so once it's finished drying, I'll slap it all back together again, let it run overnight or something in hopes of charging caps or something....

Also helpful to note (for those of you with modded systems) that the CD player functionality works WITHOUT the HuCard slot connected...I installed a switch in this thing prior to it's audio failure, I just disconnected it from the HuCard slot and fired the thing up for CD testing....helpful not to have to wire up the switch back to the slot before testing!

[Duo_R]

I just left my 8PDT switch installed, and put it in a plastic baggy in hopes of keeping it from getting wet. The plan didn't work, if you try that use something that will really waterproof the switch. It wasn't harmful though, I just had to use a can of compressed air to get it dryed. I personally wouldn't remove your switch, that is just extra work.

[Duo_R]

just an FYI - I have a hunch someone is trying to make money off this guide. Oh well I guess everyone tries to cash in on ebay. 

http://cgi.ebay.com/TURBO-GRAFX-EXPRESS-SOUND-FIX-DO-IT-YOURSELF_W0QQitemZ150329742144QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item150329742144&_trksid=p3286.c0.m14&_trkparms=66%3A4%7C65%3A15%7C39%3A1%7C240%3A1318

   
Description    
DO YOU HAVE A VINTAGE TURBO GRAFX EXPRESS HAND HELD UNIT? IF SO, ONE OF THE COMMON PROBLEMS WITH IT IS THAT THE SOUND GOES OUT. IT WILL WORK THROUGH HEADPHONES, BUT THE SOUND DIES OR IS VERY LOW THROUGH THE SPEAKERS. DON'T SELL YOU SYSTEM BECAUSE OF THAT! ON THE OTHER HAND, THIS IS A GOOD OPPORTUNITY TO BUY ONE OF THESE SYSTEMS CHEAP AND FIX IT ON YOUR OWN FOR A HIGHER RESALE VALUE! I HAVE STEP BY STEP INSTRUCTIONS WITH PICTURES ON HOW TO FIX THIS PROBLEM! IT TAKES A SMALL SCREWDRIVER, A CAPACITOR THAT YOU CAN GET AT RADIO SHACK OR ANY ELECTRONICS HOUSE AND SOME SOLDER. I WILL IMMEDIATELY EMAIL YOU THE FILE UPON PAYMENT. YOU MUST HAVE MICROSOFT WORD TO OPEN THE DOCUMENT. PLEASE READ THE FOLLOWING, JUST SO EVERYONE UNDERSTANDS: I AM NOT THE AUTHOR OF THIS INFORMATION. I COMPILED THE INFORMATION AND PUT IT TOGETHER IN AN EASY TO FOLLOW FORMAT. THE INFORMATION WAS GATHERED FROM THE PUBLIC DOMAIN AND THE BEST/PROVEN INFORMATION WAS CHOSEN. THE SMALL FEE FOR THIS IS JUST FOR MY TIME AND EFFORTS TO PUT THIS TOGETHER AND MAKE IT CONVENIENT FOR YOU. I WILL NOT GET RICH FROM THIS INFORMATION! THANK YOU! SOON YOU WILL BE ENJOYING YOUR EXPRESS SYSTEM AGAIN!