LED lightbulb "hacking" .. fixing and cooling

TonyR

IPCT Contributor
Joined
Jul 15, 2014
Messages
16,678
Reaction score
38,814
Location
Alabama
Wish I had the time to burn or inclination these days to fix a $3 LED bulb.

There was a time in the 70's and 80's I'd locate and replace a faulty $5 SCR or triac in a $150, 3 circuit traffic signal loadswitch....but then I made $10 an hour and gas was 75 to 80 cents per gallon. I could troubleshoot and repair 4 in a half hour, meaning for $25 labor and material total I could save my employer $575......

Today I'd throw that bad LED bulb in the trash and buy another.....unless I "get off" on repairing it I can make a lot more money in the same time frame fixing someone's PC, network, etc. ...but whatever cranks your tractor, I say. :cool:
 

mat200

IPCT Contributor
Joined
Jan 17, 2017
Messages
13,873
Reaction score
23,146
imho .. fix a led light bulb with disposable income dropping for many may become popular .. especially outside the USA .. ( I'm looking at you Turkey .. )
 

Jim I.

Getting comfortable
Joined
Jul 15, 2018
Messages
226
Reaction score
606
Location
Richmond, Texas
Mmmm, yeah I always purchase name brand led bulbs, Philips, Ge, Etc. and have yet to have any burn out. Some are approaching 6 yrs old.
But fix one? Maybe if I'm really really bored.
I bought a new house a couple years ago and the home builder installed some off brand LED bulbs in all the fixtures. Within 90 days we had over a half dozen of them burn out. The home builder was still building new homes on our street, so I walked into one of them that was almost finished and noticed they were using a different off brand LED bulb in all the fixtures. So instead of bothering with a warranty claim through the homebuilder, I swapped out ALL the LED bulbs in the house, over 20 of them. I haven't had one burn out since! lol
 

fergenheimer

Getting comfortable
Joined
Oct 19, 2018
Messages
341
Reaction score
754
Location
SWTexas
I bought a fixture several years ago and paid $17extra for an LED bulb. It was a "corn row" bulb. Probably within a couple of months I noticed strange spots beneath the light. It was all the LEDs from the bulb. Inspections revealed that the manufacturer used metal tape sticky side out as the conductors. When the sticky wire off, all the LEDs fell off. I would not fix that style bulb.
 

TonyR

IPCT Contributor
Joined
Jul 15, 2014
Messages
16,678
Reaction score
38,814
Location
Alabama
I bought a fixture several years ago and paid $17extra for an LED bulb. It was a "corn row" bulb. Probably within a couple of months I noticed strange spots beneath the light. It was all the LEDs from the bulb. Inspections revealed that the manufacturer used metal tape sticky side out as the conductors. When the sticky wire off, all the LEDs fell off. I would not fix that style bulb.
In the late 70's to early 80's (I can't recall) they began to manufacture a solid state relay module which consisted of a triac, snubber, optical isolator, etc. inside a small, potted box to replace existing discrete semiconductor component loadswitches. The loadswitch would allow 24VDC traffic signal controller outputs to switch 120VAC to the traffic signals in the field. There were 3 of them to a loadswitch for the 3 colors red, yellow and green. The backside was a smooth metal heatsink, coated with white thermal paste then bolted to the loadswitch frame with 2 screws to keep each relay pack cool.

Anyway, there were 3 of these 'new' SS relays inside the later loadswitches. The manufacturer placed a mylarized, 'shiny silver' label with the model number and markings for the 4 screw terminals (AC hot in, switched AC hot out, +24VDC and a ground-true DC input from the controller). The labels were sticky on one side and fit perfectly in between the screws.

All was great until these 15 amp rated solid state relay packs got warm when doing their job and a few months passed, the glue failed and guess what...that shiny myarized side facing out was conductive! Yep, some brilliant engineer though that was a good idea. Soonafter, the labels were replaced with paper, as show below.

You could depend on the label falling straight down (gravity ALWAYS is on duty) and it would short across either the AC in to AC out screws, create a conflict which a monitor would detect and throw the signals into flashing red in all directions or punch out a controller's DC output when the label shorted any of the other 3 screws to the DC input screw.

TL;DR: Don't place a naked, conductive component between 2 electrical terminals, especially if glue is used to secure it. :headbang:

SS-relay.jpg
 
Last edited:
Top