Breakfront lights not working

[Vibrissae]

So I picked up an awesome dining room set on Craigslist, which includes a lighted china cabinet/breakfront. The lights don't seem to be working, though, and I'm wondering what might be wrong with them.

Here are some images of the wiring and fixtures:
Top of cabinet
Interior light (showing on/off dial; seems to be a dimmer)

What I've tried so far:
- changing out the bulbs
- plugging it into different outlets
- poking gingerly at the connectors on top to see if anything is loose

A couple of things that might make a difference? I don't know.
- The piece is probably from the 1980s, so somewhat old.
- When I got it, it had two halogen bulbs and one regular incandescent bulb in it. (I thought halogen bulbs needed special fixtures? Maybe I'm wrong.) The former are 45W; the latter is 72W. The bulbs I tried in it are 9W LEDs.

Pretty much all I know about working with electrical things is "Unplug them first" and "Water = bad," so basic, beginner-level advice, please. ^_^

[paddedhat]

The key to this puzzle is hidden in the labels. There appears to be labels on top of each one of the "pucks" that are visible on top of the cabinet. They have valuable information on them (hopefully) and may tell you what lamp to use, and at what voltage. The next clue is the off white long box that the wiring passes through as it heads to the pucks. This is either a step down transformer or a ballast. It appears to have a label on the side. Please clean everything and report back with as much information as you can find.

[lthenderson]

I have a china hutch that looks the same. The "on/off" switch is a touch sensitive hinge on the front of the cabinet. Touch the hinge and it turns on, touch is and it turns off.  They do this so you don't have to open up the doors, reach through breakable stuff just to turn it on.

[Vibrissae]

Whew, epic dust! OK, here's the label on the hockey puck. There was in fact no label on the box. It says maximum 30W; could it have been damaged by having the higher-wattage bulbs in it?

lthenderson, I tried touching all the hinges; it didn't do anything.

[robartsd]

There was in fact no label on the box. It says maximum 30W; could it have been damaged by having the higher-wattage bulbs in it?

So there's no label on the box, but information molded into the plastic indicating a 30W max? Usually this information will include input and output power specs. Yes, higher wattage bulbs could damage the box.

[Vibrissae]

There was in fact no label on the box. It says maximum 30W; could it have been damaged by having the higher-wattage bulbs in it?

So there's no label on the box, but information molded into the plastic indicating a 30W max? Usually this information will include input and output power specs. Yes, higher wattage bulbs could damage the box.

There was a label on the puck saying 30W max; there was no label or any type on the box that I could see.

[robartsd]

The lable on the puck is far less likely to indicate a load level that would damage the box. I'd open up the box to see what is inside (disconnect from power first of course) - it could just be a housing for electrical connections distributing line voltage to the pucks.

[jpdx]

Some things to try:

+Since there is a dimmer (and it's an old one), try incandescent bulbs not LEDs.

+There are plugs on the top which will allow you to isolate the problem. Try bypassing the dimmer switch and seeing if the lights work directly with an extension cord.

+If you have a voltmeter you can test the light sockets or those plugs and see what's going on.

On first look I thought that rectangular box was a transformer, but on closer look I think it's just a housing for the dimmer. Does the dimmer knob connect underneath?

[paddedhat]

 jpdx is dead on. I would add that a 30R20 is nothing but a small reflector bulb that common to things like smaller recessed ceiling lights. It's a 30 watt bulb, which means the fixture is limited to 30 watts, to limit the heat of an incandescent lamp in the metal canister they reside in, so the 45 and 75 watt bulbs that came with it are not suitable in this case, nor is any kind of old fashioned regular bulb OK, since the reflector bulbs direct heat outward, and a typical bulb sends heat and light in all directions.The "R" is the shape designation (reflector), and 20 is a diameter code. It's 120 volts, so the box is not a transformer, nor a ballast, and it has an "A" base, meaning it's the same as any old fashion bulb, so you can use any bulb laying around to test things. IF as jpdx noted, you can disconnect the plug coming out of the box and plug the light fixtures into an extension cord, it would at least isolate the problem. Chances are, there are no issues with any wiring up top, nor in the individual pucks. Is there some chance that there is a dimmer knob  on the underside of the box, or a dimmer knob, or possibly a sliding switch elsewhere, that is simply turned off?  If not, my guess is that the mystery box is indeed a dimmer and it has failed. With a helper who possesses even a modest amount of electrical knowledge, you should be able to replace or eliminate it, if that turns out to be the issue.

[Vibrissae]

It's the dimmer! I plugged one of the light pucks directly into the extension cord and it worked.

I opened up the dimmer box to see what it looked like inside. Would bypassing it just involve detaching those black wires, and then using those wire nuts to connect the brown wires?

[paddedhat]

 It should be a matter of splicing the two wires coming into the box, to the two wires going out to the pucks.  Skin each wire back about 5/8" and pretwist the strands with your fingers. Hold the two wires together, with the ends even, and twist a wirenut on, until it puts at least one twist in the part of the wires that are insulated. The only thing that I might add to this is that factory wiring is generally done so that the circuit neutral wire is connected to the screw shell of the fixture, not the little pin in the center of the hole where you stick the lamp. This means that one side of the lamp cords in the dimmer box should have a slight ribbing or ridge on it, the other will be smooth. When you make the splice, attach the two ribbed wires together, if possible. In the event that you find that one wire is silver and the other copper, the silver wires are the neutral, or ribbed one. Congrats to jpdx on spotting the plug connection on top. I never saw such a set-up, and fully expected it to be an odd connection configuration, not something you could unplug and test. Good job so far, keep us posted.

[Vibrissae]

I did it!! The lights are all working. Thank you all for your help--I feel inordinately accomplished now. ^_^

As a bonus, I bought this lamp dimmer and plugged the cabinet into it. So now my (not very frugal) collection of ancient Egyptian god statues can be dramatically lit.