Hammond M2 series help

[Montez]

I purchased a Hammond M2 series Organ from a yardsale it worked however 5minutes into a song a high pitch squeal sound comes from the speakers. What can I do to trouble shoot this problem?

[Gtr_tech]

Reseat all the tubes for starters. remove and insert them into thier sockets a few times. Also be sure to oil that sucker....and use real Hammond oil...nothing else will work. Don't even bother with 3 in one or anything else unless you want to render the oil wicks useless.

[6267]

That's definitely an oscillation, which means something is wrong in the power amp and not the whirlygig. I would unplug it, decharge the caps, and check all the resistor values. There is also a screw terminal atop the swell capacitor housing (the tall box thing) which I believe is to adjust high frequency feedback. Try turning it a few turns to the right or left (it has no stop, so too many turns will break it). Ultimately you may want to recap. I got my m2 from a yardsale and it didn't work for a while, but I eventually replaced two resistors (after much trial and error) and it worked fine. Does it squeal even if the pedal isn't all the way down?