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This page covers table lamps, desk lamps and floor-standing lamps.
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Faulty table lamps, desk lamps and floor-standing lamps, often cherished items, are usually quite easy to repair and spare parts are available. Owners are sometimes confused, though, by the range of different types of bulb that are available.
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==Summary==
We often see table lamps and the like at Restart Parties. Often, these are quite old - maybe the owner has had them for many years and has a personal attachment to them, or maybe they simply took a fancy to them in a second hand shop. Others are relatively new and have just stopped working. Some may have frayed wires and be positively dangerous. Whatever the history there is a good chance they can be given a new lease of life.


===Safety===
==Summary== <!--T:2-->
 
<!--T:3-->
People are often very attached to a vintage table or desk lamp that maybe belonged to their grandmother, or which they took a fancy to at a car boot sale. Others are relatively new and have just stopped working. These can nearly always be fixed. Search online for table lamp spares. You should be able to find suppliers from which you can obtain all the parts you need, including brass fittings, switches, and old style cotton covered wire. You just need a very basic understanding of electricity and how to wire a plug in order to do the job safely.
 
<!--T:4-->
Check for a frayed or loose cable which could be dangerous. Using a test meter, check the continuity of the wiring from the plug, through the switch to the lamp holder.
 
<!--T:5-->
Modern LED and electronically controlled lamps can be a harder but you can still check for basic faults. You may be able to bypass a faulty electronic control and add an in-line switch to the flex instead, though not if the same electronics is dropping the mains to a low voltage for a LED lamp.
 
<!--T:6-->
A separate page demystifies the several different [[Light bulbs|types of light bulb]], and their many shapes, sizes and bases.
 
 
===Safety=== <!--T:7-->
 
<!--T:8-->
[[File:Warning03.png|30px|left]]
[[File:Warning03.png|30px|left]]
::An electrical safety test is highly recommended, including a visual check, both before and after a repair, especially for an older item.
::An [[PAT_testing|electrical safety test]] is highly recommended, including a visual check, both before and after a repair, especially for an older item.


<!--T:9-->
::As with any mains operated item, it's a good idea to have the plug on the bench in front of you before starting to work, so you can be certain you didn't forget to unplug it.
::As with any mains operated item, it's a good idea to have the plug on the bench in front of you before starting to work, so you can be certain you didn't forget to unplug it.


==Repair==
The first and most important task is to inspect the electrics. A frayed lead, cracked plug or cracked or faulty switch must be replaced. Check the fuse with a [[How_to_use_a_multimeter|multimeter]] on a low resistance range.


If the lamp uses a filament bulb, check this too with a multimeter. A faulty low energy (compact fluorescent or LED) bulb can only be positively identified by substitution.
==Fault finding== <!--T:10-->


If the lamp uses a mains voltage bulb (of whatever sort), test continuity between the plug and the bulb holder with a multimeter on a low resistance range. To do this, touch one probe on one of the pins of the plug (but not the big earth pin) and see if you can get a zero reading by touching the other probe on one of the contacts in the bulb holder. The switch may be off. Try it in the other position. Now repeat with the probe on the other pin of the plug. If you can't get a zero reading in either case then there is a break in the wire, or the switch is faulty.
<!--T:11-->
The first and most important task is to inspect the electrics. A frayed lead, cracked plug or cracked or faulty switch must be replaced. Check the fuse with a [[How_to_use_a_multimeter|multimeter]] on a low resistance range.


Lamps using a low voltage halogen or LED bulb normally have a transformer or an electronic equivalent in the base. This is harder to test but you should still be able to test for continuity between the plug and the transformer and between the other side of the transformer and the bulb. Check for any signs of overheating, or for a bulging or leaking [[Basic_electronic_components#Fault-finding_and_Repair_3|electrolytic capacitor]].
<!--T:12-->
If the lamp uses a [[Glossary:Filament Lamp|filament bulb]], check this too with a multimeter. A faulty low energy ([[Glossary:Compact Fluorescent Lamp|compact fluorescent]] or [[Glossary:LED|LED]]) bulb can only be positively identified by substitution.


Getting inside a table lamp with a decorative base such as glazed porcelain is sometimes a little tricky. A porcelain base may have a paper and felt bottom to prevent it scratching a polished surface, and you may need to remove this to get inside. Sometimes you may have to unscrew the top. You may have to pull the lead from the plug into the base in order for it not to get impossibly twisted in the process.
<!--T:13-->
If the lamp uses a mains voltage bulb (of whatever sort), test continuity between the plug and the bulb holder with a multimeter on a low resistance range. To do this, touch one probe on one of the pins of the plug (but not the big earth pin) and see if you can get a zero reading by touching the other probe on one of the contacts in the bulb holder. The switch may be off. Try it in the other position of the switch. Now repeat with the probe on the other pin of the plug. If you can't get a zero reading in either case then there is a break in the wire, or the switch is faulty.


The bulb holder may need replacing. This may be plastic or brass, and with or without an integral switch. Other brass fittings such as threaded tubes and nuts to fit them may also need to be replaced. A wide range of such parts is available online, as well as decorative and fabric-covered flex for an authentic restoration of a vintage lamp. Simply search online for "lamp parts" or "lamp fittings".
<!--T:14-->
Lamps using a low voltage halogen or LED bulb have a [[Basic_electronic_components#Transformers|transformer]] or an electronic equivalent in the base. This is harder to test but you should still be able to test for continuity between the plug and the transformer and between the other side of the transformer and the bulb. Check for any signs of overheating, or for a bulging or leaking [[Basic_electronic_components#Fault-finding_and_Repair_3|electrolytic capacitor]].


A brass bulb holder should have a screw terminal for the attachment of an earth wire. It's very important that this is connected as otherwise a fault could be lethal.
<!--T:15-->
Some such lamps have touch controls for on/off or for dimming. These too are harder to diagnose beyond simple continuity checks and a visual inspection for obvious faults.


==Types of bulb==


===Filament, florescent or LED===
==Repair== <!--T:16-->
There are 3 kinds of bulb:
* Filament or incandescent bulbs. These contain a thin wire which glows white hot when a current passes through it. They are very inefficient and have a relatively short life. Standard "tungsten" types can no longer be legally sold.
** Halogen bulbs are a newer type of filament bulb, somewhat more efficient and with a longer life. They contain a halogen gas which helps preserve the life of the filament (still made of tungsten) and so can be run hotter and hence more efficiently. The envelope is made of quartz rather than standard glass to withstand the higher temperature.
** "Vintage" or "antique" bulbs are available for decorative use. These generally have a large glass envelope and a filament in a large coil or strung between a number of supports and give a warm amber glow. However, they are extremely energy inefficient.
* Compact florescent bulbs are basically just a standard florescent tube bent into a compact shape. Both their life and their efficiency are several times greater than a filament bulb. A florescent tube cannot be connected directly to the mains but needs a ballast and a starter, and a compact florescent, instead, has an electronic circuit in its base. They tend to be bulkier than their filament equivalents and so don't always fit an existing lamp. They may take a minute or so to reach full brightness.
* LED bulbs are the newest, most expensive, but also much the most efficient type. In theory, they could be made to convert nearly all the electrical energy into light. They can be made smaller than compact florescent, so are often made in shapes similar to traditional filament bulbs. Consequently, they are more likely to fit an existing lamp or light fitting.
** Some are now made with the LEDs arranged in "filaments" to resemble a traditional bulb. The more spread-out light source may be less likely to give you spots before your eyes if you should look directly at them.
** "Virtual filament" LED bulbs are designed to mimic "vintage" bulbs. The light is directed into a piece of transparent plastic and escapes through its edges and through etchings on its surface, giving a similar decorative effect.


===Dimmable?===
<!--T:17-->
All filament bulbs are dimmable though they become even more inefficient as they are dimmed. If you want to use a compact florescent or a LED bulb on a dimmer switch you must choose one which is marked as "dimmable", and ensure that your dimmer switch is a modern one designed for low energy bulbs.  
A wide range of spare parts for lamps is available online, including brass or plastic lamp holders and fittings, switches and decorative or fabric-covered flex for an authentic restoration of a vintage lamp. Simply search online for "lamp parts" or "lamp fittings".


===What kind of base?===
<!--T:18-->
When replacing a bulb, be sure to check which sort of base it has. Mains bulbs have either a bayonet cap (BC) or Edison Screw (ES). There are different sizes of ES and less often different sizes of BC. It's a good idea to replace an old filament bulb with a much more efficient compact florescent or LED equivalent, which will also run much cooler. However, compact florescents don't always fit an existing bulb holder or shade. If a compact florescent won't fit and you find the LED equivalent too expensive, at least go for a halogen.
Getting inside a table lamp with a decorative base such as glazed porcelain is sometimes a little tricky. A porcelain base may have a paper or felt bottom to prevent it scratching a polished surface, and you may need to remove this to get inside. Sometimes you may have to unscrew the top. You may have to pull the lead from the plug into the base in order for it not to get impossibly twisted in the process.


Linear bulbs have been used for many years, for example over a shaving mirror, in a cupboard, or over a work surface. These were either filament or florescent. LED equivalents are now available for the linear filament bulbs and also for standard florescent tubes.
<!--T:19-->
The lamp holder may need replacing. This may be plastic or brass, and with or without an integral switch. Other brass fittings such as threaded tubes and nuts to fit them may also need to be replaced.


===How long will it last?===
<!--T:20-->
Halogen bulbs are generally designed to last 2,000 hours, roughly double the lifetime of an older tungsten type. A compact florescent might last 10 - 20,000 hours but will grow dimmer as it ages. A LED bulb should last 50,000 hours. Its life is limited more by the electronics in its base than the LEDs themselves.
A brass lamp holder should have a screw terminal for the attachment of an earth wire. It's very important that this is connected as otherwise a fault could be lethal.


Premature failures are far from unknown on compact florescent and LED bulbs, often due to poor quality electronic components in the base in cheap Far-Eastern examples. You may wish to keep the receipt if you decide to buy a relatively expensive bulb so you can claim in the case of an early life failure.
==External Links== <!--T:22-->
Consult Coffee Makers at:<p>
<span class="btn btn-primary" style="background:white;color:black;text-transform: none;">
[https://www.repaircafe.org/en/lamp-broken-repair-cafe-fixes/ Repair Café]
</span>
<p>
<span class="btn btn-primary" style="background:white;color:black;text-transform: none;">
[https://www.ifixit.com/Device/Lighting iFixit]
</span>


<!--T:21-->
[[Category:Fixing]]
[[Category:Fixing]]
</translate>

Latest revision as of 16:19, 31 March 2024

Other languages:

Faulty table lamps, desk lamps and floor-standing lamps, often cherished items, are usually quite easy to repair and spare parts are available. Owners are sometimes confused, though, by the range of different types of bulb that are available.


Summary

People are often very attached to a vintage table or desk lamp that maybe belonged to their grandmother, or which they took a fancy to at a car boot sale. Others are relatively new and have just stopped working. These can nearly always be fixed. Search online for table lamp spares. You should be able to find suppliers from which you can obtain all the parts you need, including brass fittings, switches, and old style cotton covered wire. You just need a very basic understanding of electricity and how to wire a plug in order to do the job safely.

Check for a frayed or loose cable which could be dangerous. Using a test meter, check the continuity of the wiring from the plug, through the switch to the lamp holder.

Modern LED and electronically controlled lamps can be a harder but you can still check for basic faults. You may be able to bypass a faulty electronic control and add an in-line switch to the flex instead, though not if the same electronics is dropping the mains to a low voltage for a LED lamp.

A separate page demystifies the several different types of light bulb, and their many shapes, sizes and bases.


Safety

Warning03.png
An electrical safety test is highly recommended, including a visual check, both before and after a repair, especially for an older item.
As with any mains operated item, it's a good idea to have the plug on the bench in front of you before starting to work, so you can be certain you didn't forget to unplug it.


Fault finding

The first and most important task is to inspect the electrics. A frayed lead, cracked plug or cracked or faulty switch must be replaced. Check the fuse with a multimeter on a low resistance range.

If the lamp uses a filament bulb, check this too with a multimeter. A faulty low energy (compact fluorescent or LED) bulb can only be positively identified by substitution.

If the lamp uses a mains voltage bulb (of whatever sort), test continuity between the plug and the bulb holder with a multimeter on a low resistance range. To do this, touch one probe on one of the pins of the plug (but not the big earth pin) and see if you can get a zero reading by touching the other probe on one of the contacts in the bulb holder. The switch may be off. Try it in the other position of the switch. Now repeat with the probe on the other pin of the plug. If you can't get a zero reading in either case then there is a break in the wire, or the switch is faulty.

Lamps using a low voltage halogen or LED bulb have a transformer or an electronic equivalent in the base. This is harder to test but you should still be able to test for continuity between the plug and the transformer and between the other side of the transformer and the bulb. Check for any signs of overheating, or for a bulging or leaking electrolytic capacitor.

Some such lamps have touch controls for on/off or for dimming. These too are harder to diagnose beyond simple continuity checks and a visual inspection for obvious faults.


Repair

A wide range of spare parts for lamps is available online, including brass or plastic lamp holders and fittings, switches and decorative or fabric-covered flex for an authentic restoration of a vintage lamp. Simply search online for "lamp parts" or "lamp fittings".

Getting inside a table lamp with a decorative base such as glazed porcelain is sometimes a little tricky. A porcelain base may have a paper or felt bottom to prevent it scratching a polished surface, and you may need to remove this to get inside. Sometimes you may have to unscrew the top. You may have to pull the lead from the plug into the base in order for it not to get impossibly twisted in the process.

The lamp holder may need replacing. This may be plastic or brass, and with or without an integral switch. Other brass fittings such as threaded tubes and nuts to fit them may also need to be replaced.

A brass lamp holder should have a screw terminal for the attachment of an earth wire. It's very important that this is connected as otherwise a fault could be lethal.

External Links

Consult Coffee Makers at:

Repair Café

iFixit

Retrieved from "https://wiki.restarters.net/index.php?title=Table_lamps&oldid=10885"
This page was last edited on 31 March 2024, at 16:19.