Yeah, it was a leap to see if the IF killer would do the trick, keep trying til we get it right.
Okay, I thought of another method to try for a white noise source, as before,
Select FM,muting off, tune to a quiet part of the dial, usually at the far ends,
With power off, tack solder a 1nF ceramic cap with very short leads, across R12(330) onto its leads. See if that does the job.
And if you look for the (FM only) front end in the manual - it isn't in there - Pioneer just bought the FM front end, they didn't make it.
I see it (AWB-030) drawn on p50 of the manual. There is no parts list, so it could be that it was built by another mfg. They say their is nothing to service and that you should change the whole unit out but I do not agree that certain items can not be repaired.