"Cydrome Leader" wrote in message
...
Mark Zacharias wrote:
"JW" wrote in message
...
On Wed, 5 Sep 2012 04:35:12 +0000 (UTC) Cydrome Leader
wrote in Message id:
:

[...]

I just confirmed that just one breath like one would use to clean
eyeglasses is enough to "short out" the small current range jack.

Can anybody else try this?

I'm going to ask fluke about this.

Doesn't happen with mine. Serial # is 96800437.


OK, I checked my 87-5. DOES NOT trigger the lead warning by any amount of
close-up hot breathing into it.

I got an RMA today for mine.

The tech support guy was basically able to cut me off before I described
the problem, and suggested I clean the jack with pure alcohol, which I
tried already. That didn't work so it's going back. It was hinted it would
take years of grime to build up on the jack before it acts weird, which
obviously isn't the case.

Also checked my 289 again to confirm "Made in America".

It is, "of U.S. and non-U.S. components" - about as I expected.

So it's back to the 73 series II for now I guess.

I'm really curious as to what the resistance is between the "shorted"
contacts, but I can't measure it without desoldering the jack, which would
probably cancel any warranty work on the unit.


DC resistance between split halves of current jacks on the 87-5 = 2.4 meg

on the 85-3 it is 30 meg on mA jack, 25 meg on Amp jack
..
The 289 appears to use optical sensing.

Mark Z.