Thursday, August 14, 2014

Scroll Lamp Cord Replacement Should Be Easier

A customer brought in these lamps the other day and said they were not working any more. They had dimmer rotary switches on the cords and the resisters in the switch were worn out. The dimmer switches can wear out and are more likely to if the lamp has a high wattage bulb or burns for long periods.



While inspecting these lamps it was apparent the cords were worn, so the customer agreed to replace the cords with new on/off rotary cord switches. The switch and the polarized lamp cord are the only two lamp parts needed to repair these lamps.


Rotary Lamp Cord Switch


First thing it to remove the shade ring, lamp shade, and socket. These lamps have porcelain sockets so there are two small screws that hold the socket body to the nipple on the bottom of the socket.




With the socket removed the old lamp cord is pulled through the lamp body. There is a lot of resistance in the cord, so it is going to take some work getting a new cord back through the lamp body. To reduce the number of bends and breaks the cord is moved through the base and the top is taken off the lamp body.




The new lamp cord is pushed up through the bottom of the lamp and keeps getting stuck about 6 inches into the lamp body. (Note: Don't forget about the base of the lamp. Run the new cord through the base before it makes it through the lamp body.) After making several attempts to thread the new cord up the scrolled lamp body, a beaded chain is run through the body to attached to the cord and pulls the cord through. This helps the cord get past the snags. The chain is attached to the cord with a small wire and soldered to keep the cord from coming loose.





The lamp body is placed in a vise while the cord is pulled through the lamp. TIP: Use a towel, rag or other cloth in the vise to protect the finish of the lamp. Never tighten the vise enough to damage the lamp. With a little more grunting and sweat, the lamp cord makes it through the lamp body.


The soldered end is clipped off.


The lamp case and top are reattached to the lamp body. The socket base is installed.



The new lamp cord is split, stripped, and a UL knot is tied. The cord is attached to the socket. Remember the smooth cord goes to the brass screw and the ribbed cord attaches to the silver screw.



The socket is screwed back on the socket base with the two smaller interior screws.


The lamp is not finished but is tested. A bulb is added and the cord is plugged in.


Good. The lamp is working, but since this lamp has a keyless socket (no switch), the only way to turn it off is to unplug it. Now the rotary cord switch can be added. TIP: If possible, it is good to test the lamp through the repair so if the final result is a non working lamp, you only have to go back to the last tested point. The cord switch can be placed anywhere on the cord. Since these lamps are a pair, the other lamp is used as a guide for the switch placement. The lamp is unplugged and the cord is split where we want to place the switch.



Using some needle nose pliers, the gap is widened. The smooth cord is cut and a notch is taken from the cord.




The new switch is opened and placed on the cord. The cut cord is placed on the switch prongs that pierce the cord. When tightening the center screw in the switch, press firmly on the switch body.






The cord is plugged in and tested again.


Perfect..... finally Total Cost < $8.00 (each lamp) Total Time < 45 minutes (each lamp)