MXR 117 Flanger problem

[eveready9v]

Hey new to the forum, just wondering if anyone's got any advice for an original MXR 117 flanger.  Passes signal at a lower volume but the effect is non existant, except when I turn the manual pot all the way down and it resonates a high pitched wine.  I'm feeling like its a component failure but wondering what to examine first as I frustrate myself with this pedal.  Any help would be awesome!  thanks
Barry

[oldschoolanalog]

Hello &  welcome!
First read this please. Serious troubleshooting requires V's:
http://www.diystompboxes.com/smfforum/index.php?topic=29816.0
Also, (now be honest ) have you done anything to it (turned trimpots or whatever)?