So my spoilers brake light had a few dead spots in it, shocker, so i went about taking it off to investigate. Some of the resistors looked corroded to hell, so i replaced them all with new resistors, but i still had the dead spots. So then i replaced all the LEDs that were dead after fixing the resistors or that looked really bad with some 3MM LEDs I had and now even less LEDs work. What gives? Its like my leds arent working with the board? i searched but only found things related to the resistors and replacing the whole board, which i dont want to do. any help is appreciated.

 

I had an LED light for the rear of my bicycle that got wet from riding all winter last year. The water and salt destroyed the board. Get yourself some perf board and new LEDs with the proper resistors. I don't really think trying to fix the original PCB is worth your time.

 

Why not just order a whole new third brake light?

 

Moneys too tight for me to spend on that IMO, Im a broke as h#ll college student and I should be able to repair it for free in theory but its just not working. I don't think its the board tho... the board looks great, and when I replaced a working original Led with a new one just as I thought the new one didn't work either... so it seems to be a problem with my Led's which i don't get. They work in other applications and it just seems they're not even letting current get through them(def in the right way!)... I have perfboard and a ton of led's around my place, worse comes to worse i might just make one for fun...

 

Yeah I can only imagine how much of a rip off buying a new one would be; there's like five dollars worth of parts there.

I count 6 resisters and 30 LEDs, for six strings of 5 LEDs each. The light says "13.5 volts 3.6" watts on the back, for a grand total of 267 mA. Thats about 45 mA per LED. If there are strings of 5 LEDs, the forward voltage drop would be around 2.7 volts per LED. Try to match the LEDs you have to the ones that are there.

Vf = 2.7 volts
If = 45 mA

Can you take a picture of your light bar to see what it looks like when it is lit?

 

Thanks for the help so far, this is what the light looks like. Two sections of 5 Led's are out. My leds are 3mm and the stock are 5 but i don't see why 3mm wouldn't work in place... I have used them interchangeably in other applications before. I dont get why the lights dont work...

 

As long as Vf and If are close, it shouldn't matter what physical size the LEDs are. Are you absolutely positive you have them installed with the correct polarity? Even if you think you are, check it agian. I've made plenty of mistakes like that before. Use the diode setting on a multi-meter. Should read open connected in reverse bias, and the meter should read with the LED's voltage drop when forward biased.