I was wonder if any of you have run into this? And I want to pass it along in case any of you do have this problem.
The lamp is a 50 watt/12 volt bulb with a GU7 base.
That is a TURN & LOCK BASE.
Their is a similar GU10 base for 120v MR16 lamps. That is a “common” size and I have seen them at Lowes and HD.
http://www.interlight.biz/mr16.htm
The GU7 12v version is NOT COMMON. In fact I called about a 1/2 dozen lighting stores and the same number of specialty lamp supplies houses in the area and they all “corrected me” when I asked for an GU7 and said that I ment GU10. That is until they looked it in their catalogs.
http://www.donsbulbs.com/cgi-bin/r/b.pl/exn%7Cgu7%7C12v%7C50w~ansi.html
Finally found one that had a couple in stock.
But I still had a problem.
The fixture is about 10ft above the floor and above that a 4 ft downrod to the transformer/track and the track is suspended about 6ft from the ceiling. So it is a difficult place to work.
Swaping with what I though was a good bulb it appeared that the fixture/transformer was bad.
So I removed it so I that I could test the parts and order replacements. The lamp, fixture, downrod and transformer are each a separate piece.
And each tested good. But when I would put it together it did not work.
What I found was the lamps had an intermitten connection.
They are made with a sealed halogen bulb with wire leads.
That inturn is mounted in reflector with a sealed glass front.
The lead come out the back and through the center of the connection post.
The post are crimped to the wire leads. But the crimp was not solid enough. Depending on the position of the bulb it would work or not work.
Edited 6/17/2006 4:55 pm by BillHartmann
Replies
Bill,
After I work over my lamps with my M-16, they usually don't work either but it does make for a fun afternoon. :)
Steve
I hate stuff like that. Use an m-16 on it.
Hmm. A poser.
Hard to tell fromthe description but i once faced what could be asimilar problem witrh some MR-16 fixtures. Let me explain.
The fixtures I faced have a small ceramic block that accepts the pins of the standard lamps. Problem was replacing the lamps wasn't helping. They could install a new lamp and it would work intermittently. Sometimes they could get it stuffed in the fixture and it would work for an hour or two and stop working.
I tracked the problem down to a small thermal overload located in the small ceramic block. An engineer at the manufacturer said that all the similar halogen light had to have a similar overload because they ran so hot that they posed a fire hazard if installed incorrectly, were overlamped or buried in insulation if the fixture was non-IC.
Took some doing but I was abler to track down replacement lead sets that included a new ceramic block, with enclosed thermal overload, and several feet of kynex covered leads. They ran $13 each as I remember it. Replacing these terminal blocks restored the fixtures to functionality.
A good thing as the store owner was a small, and relatively poor business, and replacing the fixtures, over a dozen of them, was north of $150 each.
Is it possible that the lights your working on might also have a thermal overload hidden in or near the terminal block? I too thought for a time that because they worked off and on when I wiggled them a crimp was bad. I messed with them an hour or so at a time off and on for a week before I understood I was being tricked and disabused myself of this illusion. A couple f times I thought I had solved it messing with the crimps.
I finally removed a terminal block and rigged a mechanical terminal set from a pair of set-screw wire nuts with a thermal overload I had on hand cut into one of the leads. It ran like a champ for a couple of days confirming that the trouble was in the block even though they rang true and otherwise seemed sound.
Of course I am just shooting in the dark here. Despite your description I'm not entirely clear about what your looking at. Pictures would help.
No. The heads of these fixtures out in the air and well cooled.I have positivity ID'd it as being in the bulb.Used aligator clips to connect an ohm meter to the sides of the bulb studs.Reads open.Then I can take a tool and probe around the center of the studs where the wire lead goes through and push the lead against the stud and have continuity.BTW, in this same house I had another fixture that was causing problems. It used standard bi-pin MR-16. Two years ago I had to replace several of the Juno track electronic transformers so I susepcted that again. And it would come on, but immediately go off.Bad contact between the bulb and socket. The bulb had oxide on the side of one of the pins.
I don't recall ever working with that style lamp, is this track & fixture something like "tech lighting"
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.Wer ist jetzt der Idiot
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It is standard Juno track.The transformer and head come from another company. Cen Tec or something like that. Don't remember the exact name.The heads are a little different than the Juno ones that are other parts of the house. But nothing that special.http://tinyurl.com/kso6jThe rest of the house uses the T621These are somewhat similar with the T480's.The glass on the front of the lamps is marked UV filtered and the catalog pages calls them Constant Tempature.One is shinging on a painting (print? I have not looked that close).But I am guessing that the fixtures where chosen because you get the different lenght down rods.However, IIRC when I looked up the company online they had other heads which took the standard bulbs.This whole thing was strange. The house was build in 1980 and the orginal HO. And it is a very custom designed. IIRC aboutr 4500 sq ft and no place for a family.And apparently there was some remodeling done around 1990. Those fixtures had a 90 date code on them.When I started to work on the house about 2 years ago the whole track did not work. And the HO could not tell me what siwtch(s) worked it.Finally found that the there was no track connector on it. The wires where run, but not connected.Now is in a large 2 story entry hall area with open stair case to the 2nd floor which has an open area overlooking the hall area. So the end of the track is only about 1 ft from the stairs and it is possible that something was carried up and broke the old track connector.
Avant Garde ....is weird enough for me, especially from some source even you can't find.....probably would have been easier to toss the old fixture I have to chuckle when some job has the lighting determined by some lighting "desgner " who apparently has been trippin on acid and decides on the hand blown, handpainted, one-of-a-kind prototypical fixture with oddball lamps that were made in one the former Warsaw Pact satellites....
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.Wer ist jetzt der Idiot
?