MXR Distortion + pedal problem

[lojo]

Greetings, and thanks for letting me join.
Working on a very old MXR Distortion + stomp switch died & added 9v power supply jack. It works, & looks good on the 'scope - but severe squealing. Could it be one of those little 1nf tantalum caps?

 

[VictorB]

Does it squeal when you just use the battery? Or just the power jack? the 741 op-amp may need to be replaced...

Any pics of the guts?

 

[lojo]

Does it squeal when you just use the battery? Or just the power jack? the 741 op-amp may need to be replaced...

Any pics of the guts?

Thanks for the interest Victor - I should have been more specific. Pedal works, but screams with battery or power supply. 741 seems fine. 1 nf tantalum hard to find...

 

[VictorB]

Gut shot?