This all started out with the lampshades on a pair of old IKEA floor lamps that were looking kinda ratty. The compact fluorescent 3-way bulbs were starting to show their age as they didn't seem to be as bright anymore. So time for an update of the lamps. They were still solid lamps and the first step was to change out the bulbs. 3-way bulbs can be switched to 3 different levels of brightness when in a special 3-way socket that has an additional contact. Whenever I put a new bulb in this one lamp, you would hear a loud pop and then the circuit breaker would trip. The socket did seem kinda loose and the bulb wouldn't go in straight like it was supposed to. It did work with the bulb at just the right angle and screwed in really tight into the socket. Well, time to write off the lamp as a disposable or fix it so it is no longer a potential fire hazard. Make it so.
Step 1: Break It Down...
First, unplug the lamp and put the end of the cord where you can see it away from the outlet. Working with live mains electricity is dangerous.
Next is is to get the lampshade off to see what you've got.
There is a little nut or finial that screws down the frame of the lampshade to the harp or metal piece that supports the lampshade around the bulb. The harp can be removed by squeezing it together like a spring and pulled out.
In general, lamp anatomy is pretty simple and the same for most. The wire is fed through and snaked in the lamp housing or poles. The lamp socket housing or shell is held in place by threading it on to a small section of threaded pipe at the base of the lighting part. The cover housing or upper shell can be just pressed on, screwed on, or glued on to retain the electrical socket into the housing.
Note that this lamp is an older model floor lamp which I think IKEA does not even produce any more. This lampshade is attached like an umbrella shade over the bulb. Newer models seem to be of a retainer ring that fits between the bulb and light socket with the braces radiating up from there. I went to a couple of home centers before I could find the replacement lampshade pictured here.
Sometimes with mass produced stuff, manufacturers will use proprietary fittings or will just weld or coat everything in glue into one big no-user-serviceable-parts blob. I popped off the endcap on the end of the swingarm to see how the socket was attached. I only saw the wire routed in there and figured you wouldn't be sticking a screwdriver or allen key in there to detach the socket. I tried pulling at all the parts to see what would come apart. I then played around with turning the parts to see what may have been threaded to fit together.
Step 2: Hats Off...
I searched on the internet to see what kind of parts are available for repair and to get a clue of how things were installed. It seemed there were some standard lamp replacement parts, but IKEA uses metric stuff and getting something off the shelf might not work. There were plastic/phenolic replacement 3-way switches/sockets and brass/metal cased replacement 3-way switches/sockets. I kept looking at the parts they had at the home centers before I actually tore the lamp down further.
Well, the silver metal casing seemed to move. I knew the plastic switch knob could be unscrewed. I turned the plastic piece covering the socket pretty hard and it worked loose. It was a screw off retaining piece. Good thing they decided not to glue it down. I was then able to wiggle up the socket itself.
Step 3: Switch Post Mortem...
Ah, inspecting the failed socket closer reveals that there was some arcing due to the bulb base shorting out the contacts of the 3-way switch and that one of the contact rivets had been worked loose. I do remember this lamp being used with regular bulbs and maybe fidgeting by the old folks on what was a 3-way switch may have led to the premature failure of the lamp socket. I dunno, only use a 3-way bulb in a socket meant for 3-way bulbs? I think I missed the fine print in the user manual or didn't get what the pictogram was saying, which is long gone, by the way.
Anyway, I was able to pull the socket up enough to reveal the wiring screws that attached the wiring. The wiring below the socket is wound up in a special underwriter's knot, you can look that up. It offers strain relief so that the wire is not pulled away from the socket. The bottom half of the shell seemed to unscrew but I didn't want to mess with that if it pulled off and I could not reattach it again.
It is then easy enough to unscrew the wires and go to the hardware store to get an exact replacement. Before you unscrew the wires, try to mark where the wires went or take a picture of the wires. You want to keep the polarity or where hot, neutral, and ground are connected to be consistent with the original wiring for safe and correct operation.
I then took it to my local hardware store where the more knowledgeable hardware guy was able to get me a suitable replacement 3-way lamp switch. I could just take out the socket part from the complete brass 3-way switch.
So it was easy enough to reattach the wires to the corresponding terminals on the socket. Wind the wire around the screw clockwise so when you screw down, the screw really grabs the wire and draws it in. I put some electrical tape to cover any exposed metal to prevent any accidental shorts even though it would be pushed back into the plastic shell. Orient it so that the switch shaft is pointed out the opening slot in the lamp base. You can screw on the plastic switch turn knob. Push the socket far down enough into the bottom shell so that you can screw on the top half of the shell. The switch knob will keep the bottom from rotating. Snug up all rotating parts.
Step 4: Update to the Latest and Greatest...
I changed out the compact flourescent bulb with a new LED one. LED 3-way bulbs are still relatively expensive, about 20 USD each but produces a much better quality light, instant full brightness, doesn't throw off heat, rated for a zillion hours of use and won't put off a toxic cloud of mercury if you happen to break a compact fluorescent bulb(yes, I have broken one or two CFLs while working on the house). They are even more energy efficient than a CFL.
You can now snap back in the lampshade harp. Put on the lampshade. On the lamp. Secure on top with the finial nut.
Now enjoy the refurbished lamp. And don't forget to dust off the lamp, just like you vacuum behind the computer...