8 May
2012
8 May
'12
6:47 p.m.
On Tuesday, May 08, 2012 12:36:57 PM Ralf Mardorf did opine:
Hi Gene :)
On Tue, 2012-05-08 at 11:13 -0400, gene heskett wrote:
This thing, because of the very low level of signal used, does not 'turn
on' any semiconductor junctions, so they disappear from its view. That
means you can do a very reliable test while it is in circuit, before you
warm up the iron.
When I took a chance and spent $175 of the tv stations money for it, close
to 20 years ago now, I was initially a little dubious, but that thing has
turned out to be worth at least as much as sliced bread or bottled beer,
and has probably saved me many hundreds of hours of troubleshooting time
since. That, a good temp controlled iron, and a good scope (and the brains
to see what its telling you) are the 4 most indispensable tools a techie
can have. I left out the dvm because everyone has one of those today...
On Tuesday, May 08, 2012 10:32:50 AM Ralf Mardorf
did opine:
I guess I already found the problem. On the primary side there are a 1u
50V and a 47u 25V capacitor, both 85آ°C. Thomas said I should replace
them with > 100آ°C, even if they look ok.
I've got capacitors on stock, but bad equipment for soldering. Unsolder
already was hard, but I can't get it soldered, especially since the 47u
I've got, has got a larger diameter, since it's a 35V. Reading glasses
btw. are less good for soldering, I need to find a better tool to see
when soldering. Thomas has got some special glasses.
When I turned on my 7 year old Behringer
Using its age as a clue, I think I would be gong through it with a
"Capacitor Wizard" checking the caps in the psu in particular. I haven't a clue what it may be called on
your side of the pond
though, so I will describe what it does in hopes it might be
recognizable as a euro made and named testing device.
It is a small, low power oscillator, generating about 85 millivolts of
rf signal, at a nominal frequency of 100 kilohertz, the currant it
can send through a capacitor is presented on a meter, usually
calibrated with a knob so that it reads full scale when the probes
are shorted together.
Thomas has got Hameg oscilloscopes with component testers.
Btw. the capacitors I unsoldered are broken now, even
if they should
have been ok before. Not because of heat, but to take hold of the
capacitors damaged them.
You are welcome. I hope I helped.
Cheers, Gene
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene>
A banker is a fellow who lends you his umbrella when the sun is shining
and wants it back the minute it begins to rain.
-- Mark Twain
Having a spare for that sort of thing is a good
idea. Asking if it
will fail is like asking if freshly poured concrete will crack. The
"if" is wrong, the correct word is "when", because it will, always.
:)
I'm not a fan of switching power supplies.
Good luck Ralf.
Cheers, Gene
Thank you Gene, Thomas tries to visit me in some hours.
Ralf