Author Topic: Intermittent Light Bulb Failure (Read 17511 times)

edy · « **on:** March 23, 2016, 03:25:08 am »

I have this strange problem, it's driving me nuts! In my kitchen ceiling I have 2 lights... each is a simple socket for a light bulb and then it gets covered by a frosty white globe. The lights are up around 10 foot high and I need to get a ladder and remove the globe each time I need to change the bulb.

So I have this one light that is doing a strange thing. It was working fine for months, then a few days ago it flickered a bit and went out. I climbed up the ladder, took off the globe surrounding it, and unscrewed the bulb (which is clear). The light switch was still on. As I turned it I saw some sparks and the light went back on, so I screwed it back in and it worked again for a few days.

Then this morning the light was again not turning on. I climbed up the ladder again, removed the globe, unscrewed the bulb completely this time and looked at the filament which was intact. Nothing visibly wrong with it, no sounds when I shook the bulb. I screwed it back into the socket and turned on the light switch... again I had light. Put the globe back over the bulb, ladder back into garage.

I figured all was good..... except...

... a few hours later it does the same thing! I was upstairs, my wife said it flickered a few times and went out. I try turning on the light again and it's dead again!

Now I'm not about to climb up that ladder again until I have an explanation of what is going on! It makes no sense. Is the filament broken? When it heats up after a while does it break a contact somewhere? Then why wouldn't it light up again after the filament got cold? I have to physically unscrew and rescrew the bulb in by only a tiny amount. Could it be carbonation on the contact in the socket? Why would this happen to this socket only and is moving the bulb "scratching" the carbon deposit away until it builds up again?

I can't figure this simple thing out... Someone help!

IanB · « **Reply #1 on:** March 23, 2016, 03:36:04 am »

Replace the bulb with a new one...

Xenon Photon · « **Reply #2 on:** March 23, 2016, 03:44:32 am »

broken bond wires to the screw? or bad connection to the socket wires?!
change the bulb and let us know.

Brumby · « **Reply #3 on:** March 23, 2016, 03:56:47 am »

My experiences with this phenomenon are based on the filament being broken. You might also be having the same problem, but with the break not being visible (remember, electrical connection is what matters - not visual) - but there is the possibility you may be experiencing something similar in the connections in the base which is behaving somewhat the same.....

With the visible filament break, the globe can be brought back to life by having the globe powered and manipulating the filament until it makes contact with the other side. A quick surge of current forms a weld - albeit a weak one - which will allow the globe to function for a while. Turning it off will allow things to cool down and it may cause the weld to break, leaving you with a dead globe again. It may be possible to repeat this process, but the law of diminishing returns jumps in real quick.

Answer: Replace the globe. If the problem still persists, get an electrician to check the socket.

PS. I used the above 'repair' technique in my first job as a computer operator (many moons ago). The IBM 2501 card reader we had used an incandescent light globe to shine through the punch cards to photodetectors underneath. One night, it failed before I had loaded up the night's work. So I popped the top, saw how easy it was to access - and then 'fixed' it (as above). I immediately loaded every single job that was scheduled for that night onto the input queue, crossing my fingers that it would last that long. Which it did.

Xenon Photon · « **Reply #4 on:** March 23, 2016, 04:05:18 am »

Quote from: Brumby on March 23, 2016, 03:56:47 am

My experiences with this phenomenon are based on the filament being broken. You might also be having the same problem, but with the break not being visible (remember, electrical connection is what matters - not visual) - but there is the possibility you may be experiencing something similar in the connections in the base which is behaving somewhat the same.....

With the visible filament break, the globe can be brought back to life by having the globe powered and manipulating the filament until it makes contact with the other side. A quick surge of current forms a weld - albeit a weak one - which will allow the globe to function for a while. Turning it off will allow things to cool down and it may cause the weld to break, leaving you with a dead globe again. It may be possible to repeat this process, but the law of diminishing returns jumps in real quick.

Answer: Replace the globe. If the problem still persists, get an electrician to check the socket.

PS. I used the above 'repair' technique in my first job as a computer operator (many moons ago). The IBM 2501 card reader we had used an incandescent light globe to shine through the punch cards to photodetectors underneath. One night, it failed before I had loaded up the night's work. So I popped the top, saw how easy it was to access - and then 'fixed' it (as above). I immediately loaded every single job that was scheduled for that night onto the input queue, crossing my fingers that it would last that long. Which it did.

You reminded me of this video:

MarvinTheMartian · « **Reply #5 on:** March 23, 2016, 04:49:56 am »

Quote from: Xenon Photon on March 23, 2016, 04:05:18 am

You reminded me of this video:

Love this guy!

SL4P · « **Reply #6 on:** March 23, 2016, 05:15:38 am »

Without reading all the intelligent replies
--- was it an intermittent light bulb, or an intermittent failure?

edy · « **Reply #7 on:** March 23, 2016, 05:53:17 am »

Ok, I just climbed up ladder again and unscrewed the bulb, then screwed it back in. Turn on the light switch and it works again!

Intermittent failure... Bulb constant. Only thing required to "fix" is turning it 15 degrees counter-clockwise, then screwing it back 15 degrees clockwise. Bulb is tight in socket, nothing obvious going on with the bulb otherwise. However, I do notice the metal of the bulb screw is silvery white, not copper. It kind of looks like aluminum.... Not sure if that is now being used for bulbs or not. I remember them being a shiny silver and usually copper.

MarvinTheMartian · « **Reply #8 on:** March 23, 2016, 05:55:59 am »

Quote from: SL4P on March 23, 2016, 05:15:38 am

Without reading all the intelligent replies
--- was it an intermittent light bulb, or an intermittent failure?

I'll go with the intermittent light bulb - sometimes it was there, sometimes it was not - a very unusual symptom!

Shock · « **Reply #9 on:** March 23, 2016, 06:37:32 am »

Low wattage halogen light bulb on a dimmer circuit? If so they seem to get blinky depending on what dimmer circuit is being used.

If not what type of bulb what voltage and type of circuit?

edy · « **Reply #10 on:** March 23, 2016, 06:44:31 am »

This is a normal incandescent bulb. Clear glass. Probably 60 or 75 W, nothing more. Single filament inside. The thread on the bulb is also standard, with one round contact on the bottom end of the base and the other contact being the threading around the side of the base. The light switch is just a regular 2-pole switch. One on, one off. No dimming. Switch is fine, I hear no crackling and it is smooth.

I did notice that the round contact at the end of the base was quite flat. It didn't stick out much. Nevertheless, it still makes contact perfectly fine with the socket when I screw it in. The socket looks to be surrounded in ceramic, not plastic. The bulb metal is aluminum which having done a Google search appears to be fine.

Muttley Snickers · « **Reply #11 on:** March 23, 2016, 06:55:39 am »

I have in the past encountered the intermittent problem you describe particularly with outdoor Par-38 Edison screw-in type fixtures, generally it's the centre contacts that need a slight rub with emery paper and also the centre contact in the fitting may require being brought forward slightly with a pair of pointy nose pliers, just make sure that power is completely disconnected beforehand.

Also just for the record how many people were present during the replacement process and what were their occupations ?......

wraper · « **Reply #12 on:** March 23, 2016, 07:08:35 am »

Quote from: blueskull on March 23, 2016, 04:02:19 am

There is one way to fix it, AFAIK. Charge up a capacitor to high enough voltage (say, 1000V), but not too much energy (say, 30J), then dump it in the filaments. The sudden discharge between invisible gaps will hopefully weld them together. This is commonly used in TV repair shops in China to resuscitate an image tube.

This is used for completely different reason though. To burn the conductive debris that got between the electrodes of the CRT.

Connoiseur · « **Reply #13 on:** March 23, 2016, 08:18:02 am »

I guess the problem is oxidised contacts. Did you try light sanding with 200 -ish grit paper?

If none of the remedies work, then probably the bulb is possessed. You might wanna replace or exorcise; whichever is cheaper.

RobertoLG · « **Reply #14 on:** March 23, 2016, 08:33:58 am »

Shock · « **Reply #15 on:** March 23, 2016, 08:44:38 am »

How many electronics engineers does it take for the OP to change a light bulb?

MK14 · « **Reply #16 on:** March 23, 2016, 09:26:25 am »

Delta · « **Reply #17 on:** March 23, 2016, 11:12:28 am »

Just change the bloody bulb!

dB · « **Reply #18 on:** March 23, 2016, 12:04:08 pm »

Quote from: edy on March 23, 2016, 03:25:08 am

I have this strange problem, it's driving me nuts! In my kitchen ceiling I have 2 lights... each is a simple socket for a light bulb and then it gets covered by a frosty white globe. The lights are up around 10 foot high and I need to get a ladder and remove the globe each time I need to change the bulb.

So I have this one light that is doing a strange thing. It was working fine for months, then a few days ago it flickered a bit and went out. I climbed up the ladder, took off the globe surrounding it, and unscrewed the bulb (which is clear). The light switch was still on. As I turned it I saw some sparks and the light went back on, so I screwed it back in and it worked again for a few days.

Then this morning the light was again not turning on. I climbed up the ladder again, removed the globe, unscrewed the bulb completely this time and looked at the filament which was intact. Nothing visibly wrong with it, no sounds when I shook the bulb. I screwed it back into the socket and turned on the light switch... again I had light. Put the globe back over the bulb, ladder back into garage.

I figured all was good..... except... ... a few hours later it does the same thing! I was upstairs, my wife said it flickered a few times and went out. I try turning on the light again and it's dead again!

Now I'm not about to climb up that ladder again until I have an explanation of what is going on! It makes no sense. Is the filament broken? When it heats up after a while does it break a contact somewhere? Then why wouldn't it light up again after the filament got cold? I have to physically unscrew and rescrew the bulb in by only a tiny amount. Could it be carbonation on the contact in the socket? Why would this happen to this socket only and is moving the bulb "scratching" the carbon deposit away until it builds up again?

I can't figure this simple thing out... Someone help!

You said you had 2 lights/sockets? Switch the bulbs between sockets. That will tell you if it's the bulb or the socket!!!

tooki · « **Reply #19 on:** March 23, 2016, 01:42:27 pm »

Quote from: edy on March 23, 2016, 05:53:17 am

Ok, I just climbed up ladder again and unscrewed the bulb, then screwed it back in. Turn on the light switch and it works again!

Are you absolutely positive the bulb is to blame? I ask because I had the same symptoms, and it turned out the bulb was just fine, it was the light switch that was intermittent. Next time it flickers, try switching the light switch off and on a few times. If it stabilizes, it's probably the switch. If not, then it's the bulb or the socket.

cvanc · « **Reply #20 on:** March 23, 2016, 01:50:28 pm »

Quote from: Muttley Snickers on March 23, 2016, 06:55:39 am

I have in the past encountered the intermittent problem you describe particularly with outdoor Par-38 Edison screw-in type fixtures, generally it's the centre contacts that need a slight rub with emery paper and also the centre contact in the fitting may require being brought forward slightly with a pair of pointy nose pliers

This. Your center contact in the socket (a flat metal tab) needs to mate better with the center contact of the bulb (which you said was kind of flat). A common problem (at least in my house).

Fashion a tool to pull the center tab out to a more raised position and/or put a small bump of solder on the center contact of the bulb.

JoeO · « **Reply #21 on:** March 23, 2016, 02:10:46 pm »

Call an electrician. This is a problem that is way to difficult to troubleshoot over the internet.

Audioguru · « **Reply #22 on:** March 23, 2016, 02:29:24 pm »

I suspect that the light bulb socket has poor contact caused by corrosion maybe from a leak up there or from water vapour rising into the light bulb globe caused by cooking and dishwashing in the kitchen.

Hey! This is 2016. Old fashioned filament light bulbs are illegal and are not available today aren't they? I have been using efficient compact fluorescent light bulbs for the last 12 years or more.

Cubdriver · « **Reply #23 on:** March 23, 2016, 04:12:35 pm »

Two light fixtures. Two bulbs. Swap bulbs between sockets. If problem follows bulb, replace intermittent bulb. If problem stays with the same socket, troubleshoot socket and wiring thereto.

-Pat

Audioguru · « **Reply #24 on:** March 23, 2016, 06:56:20 pm »

I had a home that was wired with huge aluminum wires that fit poorly on receptacles and light sockets. The connections were intermittent all over the place and they even smoked sometimes. I replaced all the receptacles with aluminum-safe ones.

I wonder if electrical receptacles are intermittent when they have the "stick the stripped wire in the hole and hope it makes a good contact"?


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Author Topic: Intermittent Light Bulb Failure (Read 17511 times)

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