Duo R suddenly has one of the audio channels completely gone

[edomatic]

Hi Guys,

A few weeks ago, i got myself a DUO R system, when it came in everything worked perfect for a couple of weeks, no issues at all.
However, after being able to play fine for a couple of weeks on my system, suddenly, one of the audio channels is completely gone..

I ruled out the cable ,its fine (works perfect with other Duo R at a friend's place) ..i checked the connections on the duo R's DIN8 (mine is RGB modded) but all looks very much in check there too, so i do not know what is causing it or if there is something i could do to fix this.

As a note, I have soldering skills, but i have no idea where to look first for this issue.

Can someone here point me in the right direction with this issue?

Much appreciated

regards,
Edwin

[gtsamour]

Probably you need a capacitors replacement.

[Keith Courage]

I have never come across a duo-r system yet that has needed new capacitors.

did you say this has a din 8 connection? Does that mean it is RGB modified? the reason I ask is because the original Din 5 connectors would just end up needing to be resoldered because the joints would crack for it over time.

also, is it the same for CDs as it is for hu cards that the second audio channel is missing?

[edomatic]

Hi Keith,


Yes correct mine is RGB modded with a DIN5 replaced by DIN8, the issue is the same with Hucard and CDROM ,i tried audio CD's as well same issue, only one channel seems to work

@Gtsamour,

When you say capacitor replace, you mean ALL of them or just a specific set controllng the audio?

I also want to say thanks for taking the time to respond to my cry for help! I appreciate it very much as i really am in a pinch here (just got ninja spirit Huecard today and was looking forward to some hardcore gaming..then this issue quickly calmed my joy.. )

[gtsamour]

Well Keith is right, the duo r isn't known for needing capacitor replacement but its not impossible to happen.

If that's indeed the case (and not the din-8) then its better to go for a complete cap replacement because that means they have started to die.

I would investigate further before I start replacing caps because this is uncommon for the duo r.

Try pushing the connector while the console is on and producing sound and see if the sound gets restored momentarily. If that's the case then its a cracked soldering point.

Or it could be a solder blob that got moved and is shorting something. You need to open it and investigate closely.

[edomatic]

Does there exist an audio troubleshoot scheme for the duo-R so i can start at the beginning and trace to the point of faillure, i do have the skills to do that but i need a starting point. :-)

[gtsamour]

The starting point is to determine whether your problem is something very simple (like a din8 cracked sound pin solder) or not. Start from there.

Then open and inspect what has been done to the system during the mod.

[edomatic]

Hi,

I looked carefully at the soldering done for the RGB mod and everything looks good, no visible cracks in soldering and everything connects through (gnd , 5v , RGB and Csync, no issue there)
None of the caps seem to have 'popped' on top so i need to start looking at the beginning of the audio channels IC's and follow the path and hopefully find it that way but i need some kind of audio schematic for the duo R to be able to do that.

I could go the "change all caps" way by ordering the set from console 5 but i really want to avoid doing that as it seems more a last resort thing as you do not know if it will even fix the problem

can anyone please help me with the audio schematic for the Duo R?

 

[gtsamour]

The DUO R has Rubicon capacitors by factory. Even if they have gone bad, don't expect them to be leaking or looking bloated, they will look normal, good capacitors are like that except if they have been under lots of stress.

If you do the complete caps replacement go for the console5 kit, it has excellent 105C Panasonic capacitors. I've recapped ALL of my PCE consoles with console 5 kits, even if the consoles were working fine in the first place to be on the safe side for the future.

I think the audio caps are located on the upper left corner of the board, if I'm mistaken please someone correct me.

Here's mine, done it myself


ps
focus on the audio R and L soldering points only, not the ones related to RGB as you don't have issues there.

[edomatic]

That looks very nice :-)
Mine i did myself as well, looks pretty good too, i used an RGB amp from UK with components premounted (was to lazy to make it myself ;-)

The DIN 8 connector pins are all good, no problem there the audio pins measure through from cable to board

I ordered the cap kit but man..i can't say i look forward changing all these caps, it's like a small army of them on the board..i counted at least 70 of them

Just checked and according to wiki, the DUO R is from 1993, that would make these caps are almost 25 years old so i think it's possible some when't bad but I am not convinced however that it will solve the problem but xithout the audio schematics its my only option

[gtsamour]

Well its not a small task, there are more under the cdrom part too that are not visible in this picture...
Don't do it all at once, start and finish it little by little.
There are a lot worse.... the DUO for example, it was a nightmare with the SMD caps and the traces on that one get ripped easily.
This one... they are through hole caps, much much easier to replace.

The fact that it was working ok and suddenly not without having something remarkable happen to it smells like bad caps to me....

If there are audio schematics, I haven't come across them.

[edomatic]

ok thanks for the advice !, i will take my time swapping them all out, i will post back if it helped or not, for now my DUO R will remain on the repairbench for the cap-kit to come in

Luckely i still go the little white pc engine so hucards are still very much playable for me

i want to thank you again for taking the time to answer me i greatly appreciate the help ;-)

 

[edomatic]

Hi everyone,

I am back, today, got the full cap replacement kit for my Duo-R.

So i went and replaced all the caps meticulously
The good news is i did not mess-up my Duo-R, as it still booted perfectly but the bad news is:
Still only audio through one channel..whuuuut??....

I verified my Din8 to scart cable again with multimeter and the sound pins through for both channels starting from the board's audio pins (measured on the board itself) all the way through to the scart end , no problem there so this got me very worried now

Does anyone has an idea what could be causing one of the channels to drop like this? We can rule out the caps now.

[edomatic]

Fellows,

Does anybody here on the forum have a schematic of the duo-R i could use to try and figure out why only one audio channel is working?

That would be a great help and would be very much appreciated!