[sdiy] "re-cap" when it's SMT?

[Gordon JC Pearce]

On Sat, Sep 28, 2013 at 09:36:28PM -0500, Pete Hartman wrote:
> To follow up on this....
> 
> I did audio probes, and found:
> 
> Only the left channel has the problem.
> The D/A chip (IC19, UPD63200GS-E2) left channel out (pin 11) has no
> sign of hiss.
> IC175, a 10uF SMT electrolytic--appears to be for blocking DC--has a
> bit of corrosion on the far side, and there is hiss there.

I haven't really found that electrolytic capacitors fail, and in general the results of people "re-capping" gear that is otherwise working okay tend to be pretty dismal.  It *does* sound like this one may have a problem, though.  Whip it out and replace it, and see what happens.

>From experience I've found that electrolytic capacitors really only fail in cheap crappy switched-mode PSUs (Amstrad SRD1000 anyone?).  Disc ceramics and their surface-mount versions are the ones to watch, because as well as being thermally unstable they go leaky and upset your DC conditions.

And we all know about tantalum bead decoupling capacitors, right?

-- 
Gordonjcp MM0YEQ