Fried LED

[boppa]

one thing to look at (if you are using cheapo leds from a torch well- you get what you pay for..)

look at the PIV rating of the leds
many cheap leds (often meant for torches..) have a PIV of only 5v with a forward (driven) voltage of 1.8 or 2.2v

if the PIV is too low they will likely go all day forwards, but the smoke comes out when reversed in a dc layout

otherwise all I can suggest is looking at the current drawn by the led (most arent happy if they are above 20 mA ie 0.020A)

the resistor you are using is definately well within the range I would use for a dc (or even a DCC) layout- if anything its a bit high (making the LED dimmer than it needs to be)

(to figure out the resistor you need- its quite simple)

find the `forward voltage drop' of the led (usually 2-3v depending on type and colour)
find the supply voltage
find the Imax (maximum rated current for the led)

use ohms law to calculate

ie

(supply volts - `minus' FVD)

divided by

current in amps

ie (Vs-Vled) / I

(remember that its current measured in amps- most LEDS spec in mA so for eg 20mA equals 0.02A)