I have the ADF4350 Eval Board. I can program it to put out say, 2.4 GHz and my frequency counter, which is also my 10 MHz reference, will indicate 2 400 000 000 Hz, so I know the PLL is locked. However, the lock detect LED does not light. I try both 6 and 10 ns for the LDP bit and INT or FRAC for the LDF bit, no combinations result in the LED turning on. Besides a dead LED (or being installed backwards), are there any other reasons this might be happening?