Odd problem with Halogen High Hat - troubleshooting

[-hh]

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

[RBM]

The problem with all MR-16 fixtures, is the intense heat at the bi-pin ceramic socket. Once the socket overheats, it anneals the metal in the socket causing a poor connection,which causes to heat more, and eventually self destruct. Often you can install a new lamp and it will work for a short while, then the pins will burn and it to will go out. The remedy is to replace the socket. Some manufacturers like Lightolier have quick disconnects on their sockets, knowing that they'll need to be replaced, others will require a high temperature splicing device

[John Grabowski]

Although they have a nice look I usually advise against low voltage. I presume that you are using an MR16 bulb. The socket that those bulbs get plugged into must be extremely tight. They should be so tight that you will think that the bulb will not fit into the socket when you try to insert it in. If they are not tight the socket will overheat and burn (No Flame) over time and contact between socket and bulb will be lost. Your best option is to get some new sockets and wire them in after the existing ones fail. If this is a name brand lighting fixture it may be covered by a one year warranty.

If you have a strong magnifying glass you can take a look at the lamp side of the socket for any discoloration indicating heat has been present. You can also look at the wires as they enter the base of the socket to see if the insulation is beginning to melt or discolor.

I have purchased transformers to replace on these things, but found that it is easier and maybe cheaper to buy a whole new fixture. The sockets should be available online.

[RickH]

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

[-hh]

So it sounds like that the additional insert/remove from my troubleshooting exposed enough fresh metal to make a good contact.

Will keep it in mind. FWIW, these halogen high hats have now been in service for 10 years; it kind of sounds like one shouldn't expect them to have lasted so long without earlier troubles. :-)

Thanks again,

-hh

[RBM]

Just keep an eye on that fixture. If it goes out prematurely, replace the socket