"Dave" wrote in message
netamerica...

"Phil Allison" wrote in message
...

"Ken"
"Phil Allison"
"Dave"
"Phil Allison"

The first thing to check is all the filter and coupling electros in
the
vertical and PSU for the vertical.

You need an ESR meter or lotsa luck.

Guess I'll need lotsa luck. What does an ESR meter actually
measure,
pray tell?

** It will tell you if an electro cap has or is about to die of old
age.

Does this by measuring its internal resistance or ESR independent of
actual
cap value in microfarads.

ESR = Equivalent Series Resistance.

http://en.wikipedia.org/wiki/Equival...nce#Capacitors


A good one
http://www.peakelec.co.uk/acatalog/jz_esr70.html


** Looks very nice.

Such ESR meters can also measure the ESR of cells, both rechargeable and
non-rechargeable types -the very low test current means they can check
Lithium button cells too.

The ESR of non-rechageables is good guide to remaining capacity - far
better than voltage is.

The ESR of a NiCd or NiMH cell is a good guide to its heath and ability
to deliver high currents.

Egs:

AA alkaline = 0.1 ohms new, rising to about 2 ohms at end of life.

AA carbon/zinc = 0.5 ohms new, rising to 5 ohms at end of life.

AA NiCd or NiMH = 0.03 ohms new, rising to 0.5 ohms at end of useful
life.

9V volt alkaline = 0.8 ohms new, rising to 10 ohms at end of life.

Lithium button cell ( ie CR2032 ) = 10 to 15 ohms new, rising to 50
ohms at end of life.


.... Phil


Thank you Ken, and Phil. I had no idea. Definitely want one of those.
Much appreciated.

So anyway, if my voltages look good and there's no serious ripple
anywhere, I'm thinking more and more about the electro caps, but really
don't fancy pulling each and every one out to test without having some
sort of strategy as to which to test first. Any ideas on that? Larger
ones first? What would you guys do? I truly do appreciate the help and
ideas.

Dave



Now believe I already have an ESR meter, though I didn't realize that was
one of its functions. What I have is an Extech 380193 LCR meter, which
tells me that a fairly new but run of the mill 1uF electrolytic cap out of
my junkbox has 12.5 Ohms of resistance. If I were to try to use this to
measure the caps in-circuit, how should I proceed? I am guessing that
discharging the cap before touching my test leads to the solder pads would
give me a reading, but I really hesitate to do this without some sort of
suggestion that such is a safe proceedure for my meter. Am guessing that
readings in the single digits indicate a defective device. Does this sound
reasonable? No power to the circuit under test, of course, and likely will
push in the power button a few minutes before beginning. Again, any advice
is appreciated.

Thanks,

Dave