I'll use an old video cam to see witch LED
isn't sending, Sony has an
excellent 'night view"mode witch is very IR sensitive.
Do you have the HP 150 technical reference ?
Any digital camera can see IR from leds. But if the problem is in the
receiver? Use a scope to see the signals on the foot of the IR receiver, I
think it is an "easier" way of doing that, beyond using a digital camera (or
ANY camera, I can't remember a videocamera with no IR detection) to detect
IR emission
Good luck! :D