Bell+Howell Triburst LED Light FIX!! What's a Thermistor?
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- Опубліковано 18 жов 2024
- In this video we are repairing a Triburst LED Light. We also go over the basic
purpose of an NTC thermistor and how to test one.
If you would like to try your hand at repairing an LED Light, specifically a Triburst, pay special attention to protection devices such as the thermistor described here.
We repair ALL electronics! Fill out a free estimate request at:
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Should you use a oversized NTC part instead of the same one? Something with higher current rating?
Replacing with same may blow again. They could have under-specified the component to save cost.
Another thing to note, the L (line/hot) and N (neutral) were reversed in mine. In a light socket, the center is usually the Line (hot) and the threads are neutral. This is to avoid getting shocked when changing a bulb in a live socket - unless you really try. 🙂
This LED had L (hot) wire to the threads and N to the center. The inrush current is on the L (hot), but when wired backwards, the inrush would not pass thru the thermistor until it has passed thru the bridge rectifier. It is all AC, but I think it better to have the inrush hit the NTC first. I reversed the AC wires in mine.
Oversized- fair point, if we get another in we will measure average current draw and compare with ntc specs.
Excellent info regarding how yours was wired (and how and why you reversed)! Thanks for sharing!
@@rudolphelectronicrepairllc8938 Also, 120VAC is RMS voltage. The AC peak is about 170 volts. For a short period (1/60 Hz ?) you can have 170 volts across the 5 ohm Thermistor, which is 34 amps. This is a short duration for the inrush - but the repeated heating (joules of energy) is cumulative to the Thermistor. So I am not surprised that they fail over time. 5 ohms at 3 amps is 3^2*5 = 45 watts of power dissipation. But 34 amps at 5 ohms is 5780 watts!
holy shit XD. Mine popped and was just a black disk in the bottom of the housing and was confused at the 2 legs leading to nothing. Thanks for the part number
Question when I opened mine it was already dust. I didn’t know what to order to fix until your awesome video. How would you figure what went there? Also how did you know what eating to get for the thermistor?
Great video and information, is the replacement thermistor better than the original?
you r like a doctor i thought u lost it at the end when i heard the beeps
Update: Thanks for this! I ordered the parts from China a few weeks ago and they just arrived. Only took an hour to gather everything together, desolder, and solder in the new parts (I also replaced the yellow part which was singed when the thermistor self-immolated into ash). Bell+Howell have no intention of honouring the warranty on these. They never responded.
Thanks for this video. My thermoistor belw up burning the whole light out. I was home so I was able to stop the fire.
u r in Maine?? i am in Waldo County!! my light is broken too.. that temp resistor?.. u accept drop offs? mail ins? my light has the yellow transformers.. but exact same problem.. the resistor litterally crumbled when i opned the device..err and i could even find a type/ model of what it was, until i found this video.. Maine..man..good stuff
Yes we are in Aroostook county! You can mail in by going to our mail-in page:
www.rudolphrepairs.com/mail-in-repairs
Send us an email and I’m sure would could arrange to meet you down towards Waldo county to save you a trip.
Very good work. Thank u
Your very welcome 👍
There is a video showing shorting the two leads together. What are the negative aspects of doing that?
I have this same type of light, but mine constantly flickers…drives me insane and I can’t use it. Any idea what is causing it to flicker? And what can I do to fix it? Please help me!
I have two that have failed already. Built in obsolescence to get new dales
I know very little about electronics. But I suspect that the thermistor here is intended to protect the diodes when the light is turned on in a cold building.
Excellent video. I'm going to try to repair mine thanks to this because Bell and Howell are unresponsive.
When my thermistor (found replacement on eBay) flamed out, it burned a resistor next to it that I'm trying to identify. Can anyone help with a part number and source for the yellow resistor part?
MEX/TENTA MKP
0.1 UF K X2
275VAC 40/100/21
I have the exact same problem. I am concerned that I will have to do the same repair every 2 or three months. Is there any other options? Like using a different thermistor?
I don’t have another one in the shop at the moment, but I would take a look at the other components on the input side of the circuit to determine if the amperage rating can safely be increased. Maybe a 4-5amp thermistor would give more longevity however before doing so please ensure it is safe (by checking ratings of other components on the input side of the circuit).
I saw this on other videos and others all they was solder the two broken ends of the thermistor together. For only having a resistance of 5 ohms(room temp) which is barely nothing, soldering the two ends would be ok...wouldn't it? I personally think that thermistor was overdesigned. I have repaired 5 lights this way over 1-2 years ago and all are fine btw.
Hi Rob, the thermistor is part of the design to prolong the life of the circuit, kindly see -
product.tdk.com/en/techlibrary/applicationnote/howto_ntc-limiter.html
IMO it’s a necessary part of the circuit, but you can of course delete it, totally up to you how you repair the light. Thanks for the comment!
Have done what you shoved but no luck!
Hey how can I order this part
You can get it from mouser:
www.mouser.com/ProductDetail/Semitec/5D2-08LC?qs=wgO0AD0o1vs0%252BgkOgCkmBQ%3D%3D
got 3, and i have 2 that went out so far. less than a year
Seems like a bad design..
It's "Bell AND Howell"!
The joke bell and Howell shouldn’t sell these when they fail so fast. 3-4 of mine failed in three months maybe 100 hours on them. Not even.
there are a few videos of guys eliminating the thermistor what do you think
I would definitely recommend not bypassing the thermistor.. it’s a couple bucks for the part- not worth losing a home over 🔥IMO
This NTC thermistor should do fine:
www.mouser.com/ProductDetail/Semitec/5D2-08LC?qs=wgO0AD0o1vs0%252BgkOgCkmBQ%3D%3D
@@rudolphelectronicrepairllc8938 so if deleting a thermistor from this tri-light, it can potentially burn down a house? Just curious
I have soldered up the broken thermistor contacts...been fine for over 2 years....sounds like it is a rundantcy component. Btw...if it worked correctly in the first place....why do they keep malfunctioning??
@@robraven7776 I've fixed a few without replacing the thermistor and have kept a close watch and all good
Engineered obsolescence
Poor design by Bell & Howell. I have purchased 3 of these and every one eventually fries the thermistor. Using the same thermistor is redundant. It's just going to fail again.
Agreed, poor design indeed