Vintage Synth Repair

I had my CP60M electroacoustic piano regulated, and replaced 6
electrolytes caps at the output board. Once installing the unit back,
I noticed two problems which I didn't notice before:

- There will always be a ticking noise heard in the background.

- When engaging an external effect pedal (using the effect loop
send/return) a very loud hiss noise will be heard...

I double checked the caps values and orientation so I'm pretty sure
this could not be the source for the problem...

Can anyone think of anything else ?

You can listen to this behavior in the following audio clip that made:

http://www.fileden.com/files/2006/10/13/285304/CP60M%20sound%20problems.mp3

Thanks !