On Dec 7, 3:19 pm, -hh wrote:
Hi,

I have three (3) Halogen bulb based High Hats that I installed for
hallway lighting off of a single 110VAC circuit.

One of them (#2) recently went dark. I assumed that the halogen bulb
had merely reached its end of life, so I went to replace the bulb.
Unfortunately, after replacing the bulb, it was still dark, so this
didn't fix the problem.

My concern is that I have an electrical problem further up the food
chain (and thus, more work to do to get this fixed).

First, the other two High Hats (#1 and #3) continued to work fine.

Second, my recollections are that I ran 110VAC to each High Hat, and
that each one (there's three of them) runs off of its own transformer
assembly.

Third, I don't know what brand the High Hats are. I also don't know
if this is important (eg, if it makes a big difference if I need to
replace a transformer, etc). Similarly, I don't know if a Halogen
based High Hat is one of those products that it ends up being cheaper/
easier to simply replace the entire High Hat assembly, rather than to
chase down the right repair parts, etc.

Enough background.

From here, my thoughts were to start with the easy stuff, before
getting out my multimeter,etc, finding out how easy it is to replace
transformers, etc, so I wanted to test to see if the new bulb that I
put into #2 was good or bad.

So I pulled the (new but dark) bulb/ring assembly out of High Hat #2
and pulled the same (good) bulb/ring assembly off of #1 and swapped
them (bulb/ring from #2 into HH#1, and bulb/ring from #1 into HH#2).

Lo and behold - - all three are now working again.

Okay, its "fixed" - but is it? What just happened? After all, I
kind of doubt that it was as simple as just a bad connection at the
bulb, so any suggestions or comments for possible causes of this odd
behavior? Or are the 12v Halogens notorious for making bad
connections and I've never heard about it?

The reason I ask is that I don't want to have just overlooked an
impending transformer and/or other sort of naughty wiring failure
(possible fire) that this action of proverbially "just wiggling the
wires" was all it took to conceal it for some time.

TIA,

-hh

It could also be a bad over-temperature cut out switch that finally
popped back. Halogens run pretty hot.