MXR Omni Ext. Loop not working any Ideas!

[Tungsten12]

I have an Omni unit and the ext. loop section doesn't switch the effect I plug unto it on or off, cables are good could it be in the electronics? the pedal light goes on and off when switched and the LED on the unit does too
How can I fix this problem?
Thanks

[cjlectronics]

If my memory serves me correctly, there are two major components to the effects loop on the Omni.
One is an op amp that drives the signal out and another that receives the signal back in.
The other is the bank of switch settings for post effect settings.

Your symptoms sound like a bad op amp. I assume you've tried the various post effect switch settings?