Poly caps and CapAnalyzer 88A

[Steelhack]

Ok...here is my question...I have a XBOX 360 S ripped down...It would occasionally get the red ring of death.....but when it was given to me...I could turn on..and run around menus and the internet....but I did not have a game to put it under load......so I took apart with the idea of reseating the heatsink... two poly caps near the cpu/gpu under the heatsink have a light brown leakage around their area....So I tested with Capanalyzer...and sure enough...came back bad....but then I checked the bank of 6 on other side...and they also came back bad .....I used the 88a on a LCD board..and everything worked fine.

Is it possible that just all those poly caps are bad...yet could still fire up the XBOX...or is the lower ESR of the Polys affecting the CapAnalyzer reading?

Thanks

HACK

[momaka]

Re: Poly caps and CapAnalyzer 88A

Not sure how the CapAnalyzer works, but it may be fooled by the low resistances of the CPU and the GPU that those caps filter. Also, polymer caps fail usually quite violently, so you would have noticed if they did. Probably aren't bad, but I need a picture of them to see. If you're really convinced there must be something wrong with the caps, then my suggestion is to remove them and test outside of circuit. Note that you will need a good soldering station to do this. A cheap unregulated iron may not be enough to remove caps from that board.

[PeteS in CA]

Re: Poly caps and CapAnalyzer 88A

... two poly caps near the cpu/gpu under the heatsink have a light brown leakage around their area ...

I believe polymer caps do not have liquid electrolyte. So if that light brown substance is leakage from those two caps, they are electrolytic, and have a problem.

[kc8adu]

Re: Poly caps and CapAnalyzer 88A

i have an 88a and iirc on polys and tantalums the display bargraph wraps back around on some parts.like when you squeeze the tweezers a bit harder to get a better connection.
seen on mlcc too.