[NikPrice]

OK. Here's where I'm at:

Changed R21 with 2k2. High side (12v) measures 11.9v, low side 8.2v.
R22 8.2v and 1.9v.
R23 1.9v and 0v.

I'm assuming this is a voltage divider network to give REF-L and REF-H.

IC5 Pins 1+2 1.77v
pin 3 1.9v

D22 annode 8.3v cathode 7.7v
D21 annode 6.3v cathode 7.7v

D24 pads (no diode in place) 7.5v and 9v

These voltages do seem to change a bit suggesting there is some instability in the circuit.

Now, when I power the FM4 up the display reads 86.x briefly and then rises rapidly to 105.x MHz.

Any specific suggestions on where to look around IC5?

Also, the green LED D23 starts of dim and grows dimmer as the frequency rises on the display.

Thanks,
Nik.