Just finished soldering and mounting to the board. Here are the measurements:
Measured just right after the relay click:
Left out: ~7mV
Right out: ~2mV
Testing pad closer to IRPF240 ~ -9.6V
Closer to IRPF9240 ~9.45V
After a couple of minutes, when it warms up a bit,
Left out: ~4mV
Right out ~0mV (tester is pretty cheap but I've seen it go ~ -0.1 mV as well)
Testing pad closer to IRPF240 ~ -9.55V
Closer to IRPF9240 ~ 9.4V
I've read somewhere, that the negative supply should be lower than positive. could it be that I've overheated the mosfets? I've learnt the hard way to never ever solder large 3 pin components in place for testing purposes, removing them from the pcb is nearly impossible. Or at least don't bother mounting them to the chasis if you do not have lots of experience... this is my very first build, should have bought the radiators for mosfets.