Introduction: Fixing Led Tubelights That Quit
I was building a battery pack the other day... And I needed power for a heat gun I had to use, I had no handy plugs but the one on my led shop light which is only used for daisy chaining lights together. Not for any other use.
I tried it anyway and *poof* all my led lights stopped working. Sigh. What now.?
Do not do what I have done. 79% of people who have done this have died, the other 21% will die eventually. Other possible side effects : electrocution, blinding, cuts and scrapes, stab wounds, stds stis, corona virus, burning your house and shop down, Ruining your marriage, your dog could get frightened, you might have to curse a few times and claim insurance on your car or truck which will get denied and you'll question why you had insurance.
Soldering iron, screw drivers, a bit of solder.
Maybe an extension cord.
Step 1: Disassemble
In my case I just pulled down the first set of lights in my daisy chain of led tubelights and had a look around it. It was held together by 8 screws.... I undid the screws on the side with the plug in for the daisy chain but it had nothing of interest in it so I put the screw back in and then took apart the other side. This side had an interesting circuit board in it.
Step 2: Assess the Damage
I hoped for a popped circuit breaker or fuse, in this case I only saw one thing on the board that looked like a fuse. It's the tube on the right. It should have had a little wire down the middle but the wire was burnt out and there was a little burn mark on the tube.
Step 3: Can You Repair/Replace the Broken Part
In this case it seemed obvious what happened and I can clearly see what component was broken. So now I just need a replacement fuse. Unfortunately I used my last fuse of the correct size for a homemade flux capacitor time machine project I just did. So I'll have to make my own. I won't bore you with the math but I determined the correct diameter and resistance of wire to act as a fuse in the event of a short or overvoltage. This is the same technique tesla uses in their li ion battery packs so we can be sure it's a good idea.
I cut off the dead fuse.
Step 4: Install Custom Replacement / Bridge Circuit Board
I used my Weller soldering iron and a scrap of wire from the actual dead fuse I had removed to bridge the circuit board. In my case it was easier to solder this on the back side of the board, but it makes no difference front or back.
Note: All a fuse is is a wire that mathematically will break when a certain current is run through it and they put them in vacuum tubes to get consistent results.
Step 5: Test the Repair
I plugged in the light and clicked it on and it worked like always. Then I unplugged it and reassembled the plastic casing around the motherboard and re ran the wires for the pull cord switch.
Reassembly was the hardest part of the whole project by far. I wasn't paying much attention when I took it apart and typical the board only goes in one way with the wiring wrapped around it just so and you have to line up the pull cord where it slots into the tabs and hold your tongue just right while you sandwich it all back together with the plastic. It will likely take a beer or two to get it.
Step 6: Success
Plugged all the lights in the daisy chain back in and they all worked again. Success. The fuse in this light was the first one in the chain and the closest to the wall power so it's fuse blew first when I attempted to draw too much power. All the others were protected by this one blowing.
In the future this light will not have proper current protection because my fuse is technically not fda approved csa approved grain fed hormone free sda approved store bought vacuum sealed quality.... So I will not use it as number 1 on the chain anymore, and if I plug something dumb into it I will likely destroy the light permanently. And that would be my fault. Not sunbeams or the government's or trumps or china's or covid-19's (you guys remember covid-19??).
Please tell me what you think of the instructable.
Comments? Suggestions? Pointers? Wild a crazy ideas? Requests?
Thanks for reading.