So your Duo still has quiet Redbook after full cap replacement & DW....now what?

[agt_dale_cooper]

So, I'm still trying to fix this PCE Duo...
I've done the following:
1)  Three hot dates with the dishwasher (Duo prolly needs a cigarette at this point  )
2)  Full mini/submini (55) capacitor replacement..
Sound still sucks.  I'm pissed, and want to fix...

So, I have a USA Duo that still has full sound capabilities, I've had the bright idea of comparing all the resistors between the two units, in hopes of isolating something that doesn't match and analyzing it....

I'm going over the resistors on the backside of the mobo, got some readings I can't figure out...
I'm looking at R604 (audio right channel) and R607 (audio left channel).  These are linked somehow to the two 10uF caps at the Post Op area
I've got my multimeter set for resistance testing (Greek Omega) at 20K.

R604 and 607 on the working USA unit are showing ~8.3 each.  (Positive lead on one end, negative on the other)
R604 and 607 on the quiet JAP unit are showing ~19.3 each [more than double!]

I've physically inspected these and they appear to have the same text on them, so I assume they should have the same functionality....anybody that know anything about electronics (I'm an accountant, I don't know shit about electronics...) have commentary on this observation (I'm assuming something is either out-of-whack here or it's related to the fact the caps are not identical to originals)?  I'm still stuck trying to figure out exactly what is connected to what, comparing working unit A to non-working unit B...

Any still got one of these 'quiet' units kicking about that they could have an electronic gander at?  Any other thoughts for repair?  HELP!!!

[Duo_R]

u got a bad cap somewhere. After my dishwash I found a cap that didn't have a good connection and it actually was disconnected.

[agt_dale_cooper]

Pulled all caps and cleaned all pads before dishwash...shouldn't be an issue.

Just re-pulled 5 audio fix caps, took another resistance reading....same as before.  Still don't get why this isn't the same as working USA unit.

Analyzed pads and surrounding 'sinks' (do these have a proper name?  the little holes that go through the board?  ALL caps legs except the post-op positives are continuous with ONE of these nearby 'sinks') for continuity to make sure I hadn't lifted a pad.....reinstalled caps to verified pads, same results, low audio.

Nat, what's this 'cap out on the middle of the board' thing? (I've reviewed all posts rather thoroughly of late, haven't seen your response to this...)  Maybe once located, I'll go have a multimeter fiesta out in this vicinity in hopes of finding some electronic love...[there is no 'Fiesta' smiley, it seems...]

[Duo_R]

wait so your issue is low audio? What is strange is my Duo's audio was reduce like 30% after the dishwash method. Not a big deal because just turn volume up, but I suspect a cap somewhere.

[nat]

Nat, what's this 'cap out on the middle of the board' thing? (I've reviewed all posts rather thoroughly of late, haven't seen your response to this...)  Maybe once located, I'll go have a multimeter fiesta out in this vicinity in hopes of finding some electronic love...[there is no 'Fiesta' smiley, it seems...]

It's not really out in the middle of the board, it just doesn't have much around it.

In this picture it's the red (22uf) marked cap inline horizontally with the sound circuitry, just to the right of the red power wire coming in from the back of the unit.

[agt_dale_cooper]

Hey, there's one great mystery solved...we heard which cap this was.   

Unfortunately, this was one of the 55 replaced...still working on this, anybody got insight into the resistance issue?

[Platinumfungi]

Any still got one of these 'quiet' units kicking about that they could have an electronic gander at? 

Yep, I've got a "quiet yet repaired" Duo right here.

(Even after replacing the 55 caps, laser, cd-rom "wiring harness", fuse, then going back and replacing caps again, and putting it through the dishwasher, it still has very very quiet audio. All the audio. All hucard and cd-rom. It's all there, but it's all way too quiet. I've shotgunned a fair amount of Duos so I'm pretty confident that all the work I did is fine.)

On my PCE Duo R604 and R607 are 47 kilohm smts. What are they on the US model?

Interestingly enough these two give odd readings on mine as well (I'm no smt resistor expert though):

R604 - 17.59
R607 - 18.10

I went ahead and tested the other 47s I found on the board and found them to be giving, what seem to me to be, more normal readings.

R566 - 47.3 (top of pcb)
R122 - 47.7 (top of pcb)

So, I'd like to know if the US model is using the same 47s for R604 and 607. I'd think so, but a reading of 8.3 hardly seems normal for a 47k...

[agt_dale_cooper]

Hmm...your case is a bit different than mine, mine has full HuCard/data off CD & ADPCM, but no Redbook (in-game audio streamed off CD).

R604 and 607 are the same part on both the USA/JAP (appears to say "473" on it), which is why I initally asked about the resistance..still trying to figure out what's what.  For reference, I got similar readings off R566 and R122.  Nearby components should NOT alter the resistance across one of the guys, right?  Assuming this is correct, I should be OK comparing working USA to non-working JAP.

On a lark, I jumpered R604...knocked the channel out completely.  I thought by reducing resistance to zero, might actually make the channel come back, but apparently not.  Also played briefly with the grey pot on the side of the laser assembly...increased performance a bit, but still no decent audio.  I'm willing to rule out the laser at this point, unless there's some unknown amplification entity on the laser itself (?  In this case, then, a fresh laser assembly might work...?  I may pull the laser assembly from my USA unit and rewire to the Japanese spec).

Trying to spec out this "47 kilo ohm" resistor ATM, see if I can't get something that will serve as replacement [I'm unwilling to unsolder the corresponding part off my working USA Duo], it's possible that by not providing correct amount of resistance, something's gone awry [why I jumpered it, not sure why the whole channel went out  ]

Anybody got a working-audio PCE Duo they'd be willing to tear down to have a look at these points / follow us along?  I'm willing to bet these USA/JAP boards are the same, but this would cement another variable.

RG, certainly appreciate your input here / time with the multimeter....THANKS!  [To be continued...]

[channelmaniac]

Resistance readings will vary depending on the circuitry around the resistor you are trying to measure.

Resistance in series is additive. Resistance in parallel will divide - the amount depends on the resistor values.

Please note that resistance isn't always read through resistors. Capacitors, transistors, diodes, IC chips, etc. all have resistance values when read with a multimeter.

Since you replaced all those caps at once you should look for a backwards cap or 2... (or more!) That would be the most likely culprit at this stage. You can also take a magnifying glass and look at the chip resistors. If they burn out they usually have pock marks on the black resistive material, sometimes even obscuring the numbers written on them.

RJ

[Duo_R]

Sounds like mine Red Ghost. I can turn up the volume higher on the TV and I can hear it just fine. But it is like a 30% volume reduction. Nat any ideas on this one?

Any still got one of these 'quiet' units kicking about that they could have an electronic gander at?

Yep, I've got a "quiet yet repaired" Duo right here.

(Even after replacing the 55 caps, laser, cd-rom "wiring harness", fuse, then going back and replacing caps again, and putting it through the dishwasher, it still has very very quiet audio. All the audio. All hucard and cd-rom. It's all there, but it's all way too quiet. I've shotgunned a fair amount of Duos so I'm pretty confident that all the work I did is fine.)

On my PCE Duo R604 and R607 are 47 kilohm smts. What are they on the US model?

Interestingly enough these two give odd readings on mine as well (I'm no smt resistor expert though):

R604 - 17.59
R607 - 18.10

I went ahead and tested the other 47s I found on the board and found them to be giving, what seem to me to be, more normal readings.

R566 - 47.3 (top of pcb)
R122 - 47.7 (top of pcb)

So, I'd like to know if the US model is using the same 47s for R604 and 607. I'd think so, but a reading of 8.3 hardly seems normal for a 47k...

[Platinumfungi]

I'd say mine only has about 10% audio level capacity. If you turn the volume ALL the way up on the tv you can barely hear everything.

[nat]

I know folks keep saying this, but these are prime symptoms of a bad cap, an incorrectly installed cap, a cap shorting to ground via leaked electrolytic (shouldn't be the case after so many dishwasher runs), or a cap not making good contact at one of it's contact points. I'd start by replacing any caps you didn't replace the first time through. It's probably not what you want to hear, but these volume issues are caused almost exclusively by capacitors. If you are getting any sound at all, the sound hardware itself is functioning.

I've never seen a resistor go bad on one of these. This doesn't mean it can't happen, but I'd be really surprised.

[agt_dale_cooper]

Hey, I hear it every time somebody says it...I did a near full install before the dishwash and then pulled everything (including ones I hadn't replaced prior), sent through the dishwash, then reinstalled fresh.  Sounds to me like RG knows his way around a board as well, and he's got the same results...shit, what am I saying, we ALL know our way round the board at this point!!!!!!!   

Used RG's guide (being able to print that bad boy and have it at your side while outside on the balcony with solder setup and cocktail is PRICELESS!!!), and provided all the polarities are correct on it, they're correct on my install...

I'll try the dishwasher again tomorrow, I suppose....[I've seen your prior posts about having a unit like ours and solving by DW....]
Maybe a good soak would help....?  What are we soaking in?  Gallon bottle of alcohol?  Wow, that's gonna be entertaining....haha!!!!

[Zeon]

ARRGH! I'm in the same boat as Red Ghost. Total cap replacement, 3 dish washes, nothing, nada, zip, zilch change in audio level.

The audio is whisper quiet on even the highest volume, same level for chip and redbook audio. The headphone audio is only slightly louder and static free unlike the audio from the av port.

I have quadruple checked that the caps are soldered in good, are in the right way, and making good connection with their contact points. The caps were brand new and my work is fine so please don't dismiss this as a cap issue, 3 people with plenty of soldering experience who have followed the same procedures and have had similiar results must mean something. There has to be a second, unknown, less likely problem that causes audio issues on duos.

I have spent weeks in this particular duo and it is driving me nuts. I am nearly at my wits end. My only guess is that one of those other small rectangular black caps on the underside of the board are bad but I seriously doubt it. If anyone has any new insight I am all ears...

[omnedon]

FWIW i've seen about 4 DUOs like this. They are all still 'part' units, as repair was not possible. I've tried chemical cleaning of the boards, checked every trace, etc.

So far all they have been is an incredible time sink.

The first time I posted about this problem someone posted that I obviously had soldered something wrong. 

Well, at least this misery has company.