Saab stereo question.

1991 Saab 900s, factory Clarion stereo, no amp or equalizer.  The rear speakers were quite sun dried and the front ones didn't look a lot better so I replaced them all.  Upon reinserting the stereo (removable for security) the sound only came up to around 25% of what it was.  Hmm.  I chucked the rear ones, but did reinstall the fronts with the same results.

Is there a hidden spot you jam a paper clip into that I don't know about?  I have no problem springing for a newer DIN 1 unit, but I don't need all that.

Thoughts?

If it's like the one in my 1991 convertible, I cleaned the contacts on the back of the unit where it connects to the mount.  Brought my sound back until the rest of the electronics in it died...