Odd Duo Audio Issue

[Duo_R]

Nat - well I removed the large caps around the pre and post amp area. I found that I had left some residue (it wasn't really noticeable but it was there). I really cleaned it up good with alcohol and swabs (diluted alcohol with water) and cleaned up very nicely. I was debating a dishwash since I found a problem area. Maybe I should solder th caps back and then test the unit again before dishwash. Of course if I have th caps off it might be a good time to do that.


UPDATE: The Duo is running on normal cycle right now.......

[ogre]

Is dishwashing the board necessary? When I changed the caps in the op amp section I scrubbed the pads with a q-tip soaked in alcohol. I also had to change the caps located in the front right corner to get the laser to read properly. Maybe I will change them all and give this  a shot if I ever get it to work again.

[Duo_R]

what is wrong with yours Ogre. Since the static audio was really bugging me (and I replaced almost every cap) for me it was necessary. Of course I wouldn't have done it if I didn't have a Duo-R on the way from the land of the rising sun.

[ogre]

The problem with my Duo is the fact that it no longer powers on. The Voltage travels to the point of the diode right next to the main fuse but not after. I think the diode is at fault , but i have not had the time lately to probe further. So for now I am using a Duo R I purchased from the seller on Ebay thats premodded RGB.

[Duo_R]

Hey I bought from the same seller I think. Was it Doujindance? Let me know your thoughts on the Duo-R. I am waiting for mine to arrive.

You know I would post up your Diode question on the Gamesx.com forums (mod and repair) and see if Lawrence can answer that one. He had a schematic once I believe.

The problem with my Duo is the fact that it no longer powers on. The Voltage travels to the point of the diode right next to the main fuse but not after. I think the diode is at fault , but i have not had the time lately to probe further. So for now I am using a Duo R I purchased from the seller on Ebay thats premodded RGB.

[Duo_R]

Nat - need your help here. Did 2 soap cycles, then 1 cycle just water. Dried really well with fans, and let sit for 5 days. There is no sound now. I let it sit on for about 1 hour. I can turn the volume way up and hear very faint video game audio, but it is very quite. Please let me know your thoughts...


UPDATE - so I checked out some caps, I replaced one that was a little suspicous, and re-flashed the caps on the bottom of the board (just held the solder iron melted solder and then let cool). Slapped it back together and full sound...no static!

Also - for some reason I didn't lose my saves even with 3 cycles.

[nat]

Great, I'm glad to hear it. Another Duo saved! Should be good for years to come.

[Duo_R]

Nat - thanks for replying back. Ok this is whats wierd, the sound periodically goes out seams like every few times I power it on. Should I start replacing some caps again in the sound area? When the sound is out if I turn the volume all the way up, I can barerly hear it. It never comes back on when it powers on like that. However, turn it off, wait a while, back on and it is good. Very strange. Right now it is ok. Suggestions? I replaced EVERY cap except for the 3.3uf cap, and 2 other caps around that area. Very strange (I think this Duo doesn't like me).

[nat]

You know, that's interesting, and I actually had a case where I repaired a Duo for someone and after I sent it back they reported something similar. Because of the individual in question, I thought they were full of shit to be perfectly frank, but after hearing your story maybe they were telling the truth. It's odd because I tested that person's Duo for like 3 hours straight on two different occasions and it had no audio problems at all during that period of time. Before that instance, and now yours, I have never otherwise heard of such a phenomenon. I would replace any caps you haven't already replaced, but it seems doubtful the ones in the area you specified have any tie to the audio system. But the bottom line is, if the issue persists, there is a cap somewhere that is acting up. If you've replaced them all, it means one of the replacements is bad, was damaged on installation, or was installed incorrectly. You might try reflowing the solder on all the replaced caps in case it's a bad solder job making a shoddy connection somewhere. Sometimes the problem isn't visible and you just have to give in and do it all over again.

[Duo_R]

yeah most of the time it is fine. The static issue definitaly is gone. Note - before I dishwashed, I used rubbing alcohol and removed all visible goo from the old caps, and the static was still present. So one problem fixed, but another underlying problem is present. I suspect a bad cap somewhere...

[Duo_R]

Nat - it has been fine the last few times I have powered the unit. The thing I am noticing is the volume seams to be lower, maybe about 25-30% lower than normal. I have to really turn up the sound, my Duo-R is much louder at the same volume level. Does this point to a suspicious cap in the amp area?