Why can't I get my LEDs to light?

[stu_the_flat]

I bought two 6.1s boards. Both work well with the current LED's that are on the tanks hull. however they come supplied with LEDs in the packet, that I need to get working but I can't. I am plug them into channel 2 (aim light) and 4 (Head light) I've tired both polarities and holding G + left stick forward encase they where turn off.

They both don't want to light, what else can I try? Its two LED's so I can't imagine that they are both faulty.

Any help appreciated.

[john1970]

It possible that they are for the IR system emitter bulbs

[lmcq11]

Your control board/LED setup might require a resistor on the + wire.

[Jofaur86]

Hello, Found on this Forum, post "electronics HL" by "Jarndice" may I quote? may be the solution?
by jarndice » Thu Mar 11, 2021 3:39 pm
A few points here, LEDs have two wires coming out the back,
One is longer than the other, knowing which is which will tell you which is positive and which is negative,
The Heng Long Version 6.0 control board has a light selector switch so merely plugging in to the correct socket will not work if the switch has not been activated,
Indeed most secondary services on the Heng Long version 6.0 MFU are switch activated so just because everything is plugged in does not mean it will immediately come to life, it has to be switched on.

[stu_the_flat]

It possible that they are for the IR system emitter bulbs

Doh! Yes you are 100% correct! I'll go and hide in shame now!

[Jofaur86]

[Herr Dr. Professor]

Uh oh: wise guy alert! "One is longer than the other, knowing which is which will tell you which is positive and which is negative." Am I missing something (as usual)? Which polarity is the longer (I'll figure out, then, which polarity is the shorter."

[tankme]

Longer leg of the LED is the anode (+) and the shorter leg is the cathode (-). If the legs have been cut you can still tell which is which by looking at the plates inside. The cathode is the larger plate looking down through the top of the LED. The cathode can also be designated by a flat spot at the base of the LED on the cathode side.

Most LEDs are around 3V. You can rig up a simple tester by connecting them to a 3V battery source (2 AA batteries in series). I wouldn't try to test them off a main 7.4V battery or will more than likely blow the LED. They make a nice popping sound and smell really nice when they go... If you suspect it's an IR LED, you can look at through the video of your phone. It can see the IR light.

Not enough current or voltage can cause the LED not to light. Too much voltage will blow the LED.