CMoy Troubleshoot

[seanohue]

Well finished my CMoy today and I just turned it on and the problem is that I can hear the music but it is extremely fuzzy. Also, I can only get sound in the right ear. My voltage rails were fine and the battery is brand new. Could I have a few suggestions as to what I ought to do? Oh, and this is really noob but would solder contact with other contact points have any affect? I was extremely careful to isolate the solder to each pin but a few of them might be touching. I am using a plastic enclosure so I doubt that it is shorting through the case.

 

[Pars]

Quote:

Originally Posted by seanohue Well finished my CMoy today and I just turned it on and the problem is that I can hear the music but it is extremely fuzzy. Also, I can only get sound in the right ear. My voltage rails were fine and the battery is brand new. Could I have a few suggestions as to what I ought to do? Oh, and this is really noob but would solder contact with other contact points have any affect? I was extremely careful to isolate the solder to each pin but a few of them might be touching. I am using a plastic enclosure so I doubt that it is shorting through the case.

Yeah, solder contact to another point is a short, so that will definitely have an effect. You asked about the pot wiring yesterday... had you tested the amp before you put the pot in? At any rate, read Tangent's troubleshoting guide and do a search as there are countless troubleshooting threads already here on head-fi.

 

[NeilR]

After you check for shorts, take a real close look at the wiring to make sure nothing was crossed between channels, especially the feedback loop.

 

[seanohue]

Yea there is some solder that I just cant get rid of with the braid. I think I'll just scrap it and try another instead wasting everyone elses time

What stuff should I do next time to make it near fail safe?

 

[Pars]

Before you do that, it would help if you posted some pics (closeup) of both the top and bottom sides of the board... it may not be as bad as you think it is and fixable. Barring that, take a magnifying glass and an xacto knofe or something like that and but between the pads where you think you may have solder bridges and see if you can clean them up that way. You at least have some sound... many dead shorts would have exhibited more serious problems than that.

Do you have a meter (DMM)? If so (advised), you can remove the opamp and measure (ohms or resistance) both from each pin of the socket to ground, and from pin to pin to see if you have proper connections, shorts, etc.

 

[seanohue]

Ugh I wish I wouldve thought that of that earlier but its too late

Already in the garbage can. I did figure out my soldering technique was wrong though so my next try should be a lot neater.

 

[mono]

If braid won't pick up solder, it can help to put a lot of flux on the braid. That also seems to help transfer heat through the braid, so you can heat through the braid easier... assuming you were previously heating the braid, not the solder, to soak up the solder. When all else fails, don't just try to get the little bit of solder in the way, get all the solder in the area cleared off, adding back some solder later if necessary.