No sound on right sound channel (ADPCM fixed)

[Duo_R]

Ok, if you haven't been following along, I got a US TurboDuo that has had every cap replaced, sound has been restored but the overall volume has been reduced about 30%, but it is static free and no fade in and out. The main problem I am having however is there is no ADPCM sound. Let me clarify since I want to make sure I am describing the problem correctly.

The best example of what is wrong is when you play YS III, at the beginning of the game you follow Dogi to his house and a girl comes out (I think her name is Maria). She walks up to you but you hear nothing. That is ADPCM voice sample correct? Any idea what could be the source of the problem? So far I have replaced:

* EVERY cap on the TurboDuo except for the 3.3uf cap
* OKI5205
* OKIM41464-10 x2
* M51131

I haven't replaced the 4558 Op amps and today I was thinking that this might be my issue. Remember when I said the sound was reduced by 30%? That happened after I dishwashed the system, and maybe the OP AMPS were damaged somehow. Obviously the total sound was reduced in volume, but maybe the one related to ADPCM was damaged?

This is my original US Turbo Duo and honestly I just keep working on it because it has some sentimental value to me. Now the sound works fine, the games play great....should I just forget all the hassle and just enjoy games on my Duo-R??? Or do you think we can solve this bitch?

[esteban]

The best example of what is wrong is when you play YS III, at the beginning of the game you follow Dogi to his house and a girl comes out (I think her name is Maria). She walks up to you but you hear nothing.

Ahhh, did you equip a nut from the Roda tree? It turns out that amino acids in the Roda nut can cure this character of her muteness. She then thanks you and provides you with a extremely useful piece of information.

Years later, a large pharmaceutical conglomerate form Esteria begins marketing these amino acids, under the brand name "Rodanol" to cure Pharyngitis.

[override]

Duo_R

I'm sorry to hear that those two chips I sent you didn't fix your system the way you were hoping...When you replaced the M5205 OKI and the M51131L did you replace them with new or used known working chips? Just curious....Also you mentioned replacing op amps, to be honest I believe that would be the next best route to go with! They are enexpensive to replace, usually less than a dollar a piece....If it were me I would start with the three I have circled in this picture, those are tied in from the M5205 OKI straight to the CD Pins.



I have a PCE Duo that has done this same thing to me and I have never gotten it back out to try and fix it, ofcourse at the moment it has two chips pull from it but other than that it still had this same sound issue. 

If those dont work I have 2 other chips you could try replacing, I believe I can get them for you aswell! 

[Duo_R]

Estaban - thanks for the laugh =).

yeah override, I appreciate u sending those chips, we are just doing the process of elimination. I will send u the IC's that I extracted since most likely they were fine. Yes the other ICks came from a system with no ADPCM issues. So next are the OP AMP. I could use some help finding a direct replacement since I want to make sure they will be drop in that fit.

Also any tips removing the old 4558's? I almost took one off but I literaly had to lift one leg at a time and it was a little tedius.

Erik

Sent from my Blackberry Tour

[override]

yeah override, I appreciate u sending those chips, we are just doing the process of elimination. I will send u the IC's that I extracted since most likely they were fine. Yes the other ICks came from a system with no ADPCM issues. So next are the OP AMP. I could use some help finding a direct replacement since I want to make sure they will be drop in that fit.

Also any tips removing the old 4558's? I almost took one off but I literaly had to lift one leg at a time and it was a little tedius.

Erik

The Tip I would give to you on removing then would be either using a heat gun like I told you that I do, or use desolder braid, get as much up as possible and lift each leg at a time, if you could get your hands on a hot air rework station that would be even more convenient! Hell if you know anyone with some soldertweez thats the best route! On the Op-amps, I believe any general purpose SMD 4558 will work! They should be the same size.

[Charlie]

If I may:
"* EVERY cap on the TurboDuo except for the 3.3uf cap
* OKI5205
* OKIM41464-10 x2
* M51131
I haven't replaced the 4558 Op amps ..."


Assuming we're talking about the same unit that I have in my notes:


1. Good that you've done the typical legacy cap replace; we all know about that.
2. Why the M51131?  It's not part of the ADCPM audio.
3. Doubtfull the memory is the problem, it would show up elsewhere also
4. Good on the 5205, it IS the ADCPM, after all.
5. I think U503 is a 4558 (among others), that's also ADCPM.  But all the other 4558's are not ADCPM, so if you have any audio at all (CD, music, game sounds), don't waste your time replacing them.

Specifically, if you all other audio except ADCPM, the only significant active components are U502(the 5205) and U503 (again, I THINK it is a 4558).  Of course, the data that drives the ADCPM comes from the MCU and CPU, but if they were bad, you'd have a lot worse problems than just bad audio.  The passive components are C652,C623,C653,C621,C622.

Finally, if, again, you do have all audio expect ADCPM, and given what you have already replaced, I'd look at U504 (usually a 4053), the audio switch.  This is the only component that is common the the ADCPM and the other audio; it actually switches the amplifier/speaker circuit from ADCPM to {other audios}.  You could  check and see if U504 is even being TOLD to switch at the appropriate time on pin 9.

Of course, if you have a different system than I think you do..??

Good luck.
Charlie

[kattare]

I have a unit here with a similar issue.  Had only the blips and beeps type audio, no redbook and no adcpm.  Replaced all the leaky caps, and that brought back the redbook 100% and the adcpm to about 20% volume.  With no more caps to replace, I flipped the board over and found a ton of leakage on the other side of the board right in and around U503.  So replacing U503... you think that would bring the adcpm to 100%?

[kattare]

Hmmm... I should have played with it more before posting.  I lifted 4 of the pins on the 4558 (IC503) and was going to start working on the other 4 when I realized that it was horribly gunky underneath the thing.  So I just bent it up, cleaned out underneath it, bent it back down and resoldered the 4 pins.  adcpm seems to work pretty good now, around 80%.  Not sure where I'm losing the 20%, but I think I'm about just about gtg with this repair.

Gotta hand it to you guys... I wouldn't have known to look at IC503 without this thread... It woulda been ages before I would have thought to look at the back of the board for leakage that had seeped through.

[Charlie]

Glad to be of help, but I can't help wondering about this statement:
"I wouldn't have known to look at IC503 without this thread"

U503 was clearly mentioned in the thread:
http://www.pcenginefx.com/forums/index.php?topic=960.msg113601#msg113601

Or maybe the explanation was not clear enough?

Charlie

[kattare]

Charlie, LOL, your explanation there is awesome.  Appreciate the link!

To be clearer, I have a pile of Duo's here, and this particular one would have made it's way to the bottom of the pile to be looked at "ages from now" if this thread hadn't piqued my interest.  ;-)

[Charlie]

" have a pile of Duo's here"
Cool.   Let's tackle them all!

Charlie

[Duo_R]

Ok update to the ADPCM saga, IC503 replaced last night. No change. Now IC504? I feel like I am running out of things to replace..... Any sources for this part or will I have to swap from another Duo? So much has been replaced already (see my post earlier).

[Duo_R]

Oh and Override I still owe u those chips. Please PM ur address again. Thanks!

[Charlie]

"No change. Now IC504?"
Maybe, maybe not.  I'd do some more testing, if you can (I don't know what equipment you have).

More detail on ADPCM  (why didn't anyone tell me I was spelling it incorrectly!???) audio:
1. Out U502,  pin 10
2. Through C652, a .1uf (you DID replace this, yes?)
3. Through R657/C623/R688 (replace C623, yes?)
4. Into pin 6, U503
5. Outof pin 7, U503
6. Through C653, a 10uf (replaced?)
7. Through R654/C621/R656 (C621?)
8. Into pin 2, U503
9. Filtered by C622 (replaced?)
10. Outof pin 1, U503
==> any of the above caps, if leaking, would affect the audio

Pin 1 of U503 feeds into pin 4 of U504, an audio switch.  When switched on (via pin 9), the audio comes out pin 5.  At this point, it is mono.  It then splits, via R627 & R629, and is amplified by the left and right channel circuits.  If you seem to have good audio out of both channels when using other, non-ADPCM, audio, this is probably ok. 

So, you might want to A) check more closely into those components mentioned above, and/or B) temporarily jump
U504, pins 4 & 5 together.  If there is no change, U504 is probably already turned fully on via pin 9, and is ok.  If there is a big change, either U504 is turned fully on (again pin 9), but is NOT ok...or it is not being turned on at all.

Overall, if you have sufficient equipment, I'd use a 'scope and view the ADPCM audio at the in's and out's of the various amplifier stages, to make sure that each stage actually is amplifying.  If you have a good unit to compare to, so much the better.

Kind of hard to do this via "remote control"

Charlie

 

[Duo_R]

as far as equipment I only have a multimeter. I can certainly try to jump pins 4 and 5 (you have done this before correct?).

I will check those caps, but as stated all the caps on the topside of this US Duo have been replaced. Again here is my problem:

* Overall sound reduced about 30% after a dishwash method clean (but the scratchiness was fixed)
* All sound works but there is NO ADPCM sound