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From your electrical idiot here,
I've been trying to convert my monsoon head unit to blue LEDs for about 2 weeks with no success. I have 390 ohm resistors which according to a resistor calculator, should be just fine for my LEDs. I've soldered the damn thing so many times that some of copper the lights connect to in the back came off so I scratched off the anti solder film higher up on the circuit and soldered to that for some of the lines (you'll see in the pics, looks really janky but according to my multimeter, it works). So did I **** up my display with my tomfoolery? I'm so confused why they still don't light up. Please help! Thanks!
It looks like you connected the resistors in parallel to the LEDs (i.e. the resistors and the LEDs share their positive and negative connections). Resistors for LEDs have to be connected in series with the LED - current flows through the resistor and then into the LED.
So basically you need to remove the anode (positive) end of the LED and the negative end of the resistor from the circuit board then connect the ends so that current flows from the positive trace on the board through the resistor into the anode of the LED and then out to the negative trace on the board.
It is critical that you get the orientation (positive/negative) of the LED correct. The current will only flow one way (it is a diode so it blocks current in the reverse direction). If you install the LED backwards it will never light.
i thought resistors didn't have a positive and negative. the way i have it now is the current flows from the board to the resistor and then to the positive side of the led. i made sure to triple the positive and negatives with my multimeter and also used this site for reference http://xse.com/leres/ss/leds.html
Resistors don't have positive and negative but LEDs (and other diodes) do. Are you sure you got the correct leg of the LEDs? The anode (positive) is the longer of the two leads (before you trimmed them). And are you sure that you have the traces on the board in the correct polarity? Because otherwise it looks like it should be working.
I am 100% positive about the LEDs and about 70% positive about the board. I used the link I put early to double check. I'm going to go get a digital multimeter soon instead of my analog one and we'll see if that makes a difference
so it turns out the radio wasn't sending any power to the circuit board lights at all. explains why my lights suddenly went out a few weeks ago. time for a new head unit
02-25-2016, 04:46 PM
Monsoon head unit LEDs 
so it turns out the radio wasn't sending any power to the circuit board lights at all. explains why my lights suddenly went out a few weeks ago. time for a new head unit