Halo recessed lighting transformer buzzes and quits...twice

[Anthracinus01]

I'm pretty new to using forums for this kind of thing and what I've read suggests that most people here know a lot more about home repair than I do. I'm just trying to fix my dad's "reading-in-bed" lamp which is a Halo ET400 LV, operating on a dimmer switch. By his report, it worked fine for several years and then quit. Turning on the switch resulted in a buzzing sound from the Halo Lighting QE1292PK transformer in the ceiling. Seemed pretty simple to order a new one and hook it up, which I did. When I tested it, the light worked like a dream...once. Second time I threw the switch, the exact same thing happened as before--buzzing transformer with no light.

For the record, yes. I know transformers buzz but it wasn't buzzing like this when it was working properly.

If there's anyone out there who can lend a hand with this, it'd be much appreciated. This thing's been quite a hassle.

[HayZee518]

dimmers

check out your dimmer carefully. many of them don't like transformers because the dimmers produced a chopped a.c. wave.
the new cfl's all have a small transformer.
dimmers use a gated triac to dim the circuit. the gate is d.c.
the dimmer doesn't produce d.c.

[Anthracinus01]

Well this serves as a pretty good example of how most here seem to know a lot more than I do. I don't really know what most of that meant but I get that you're suggesting the switch might not be compatible with the transformer. I have difficulty believing that this would be the case given the following facts: 1) this light was professionally installed by reputable contractor when my parents added on to their house. 2) The light ran flawlessly for over 15 years. And 3) There's another fixture exactly like it just over my mother's side of the bed that continues to operate perfectly.

It's entirely possible that I'm just showing the depth of my electrical ignorance in stating those things, though. Oh...and I don't know if this matters, but you mentioned CFL's. This fixture doesn't run them. It runs a 3-50 watt halogen bulb.

[HayZee518]

lights

ok, then check out the dimmer on your mom's side of the bed and get a duplicate.

sorry I misread your post. Metal Halide bulbs. ok.

[HayZee518]

quote from HID lighting

Continuous dimming capability increasingly is becoming available for electronic HID ballasts. Dimmable electronic HID ballasts are available for wattages from 100–750W; for both metal halide and high-pressure sodium lamps; and with the ability to join 0–10V DC, DALI-based and proprietary control networks.

Examples include the Empower digital ballast (0–10V DC dimming of 157–750W metal halide and high-pressure sodium lamps); GE UltraMax eHID ballast (250–400W quartz or ceramic metal halide); Metrolight SmartHID Plus (dims 450–575W metal halide and 100–600W high-pressure sodium lamps using proprietary digital interface); Philips Advance Dynavision (0–10V DC dimming of 320–400W pulse-start lamps with automatic 15-minute warm-up) and CosmoPolis programmable digital ballast (DALI dimming for ceramic metal halide lamps); Sylvania Quicktronic QTO (0–10V DC continuous dimming or stand-alone step dimming of 100–200W metal halide or high-pressure sodium lamps in outdoor applications); and Universal Lighting Technologies 210W ballast (0–10V DC dimming of Philips 210W C183 metal halide lamp, with automatic 15-minute time delay).
- See more at: Spotlight on Dimming | EC Mag