The last few days I've been trying to build a transmitter so my computer could control my digital receiver(Denon AVR 1802). I have made both circuits posted on but they both don't seem to work. If i place a standard red LED in the circuit I can see it flickering when I send some signals with Winlirc. But as soon as i put in an IR LED, it doesn't seem to worlk. I have tried 4 different LEDs but no response from my receiver. I tried all kinds of repeats and i held the circuit right in front of the receiver, still nothing. Why won't my receiver respond to the signals i send it? I learned winlirc the signals from the original remote control, and that works perfectly. What can I try to get it working?