RM4 issue

[disk11]

I've got a problem with slot 2 (upper right) of my RM4

Before, it sometimes didn't like the Diablo in there, and would just put out silence. Now, the module in the slot lights up along with the active module and when I switch to that channel I get very, very low output of mostly treble fuzz.

I tried blowing out the slot with compressed air and using electrical contact cleaner, but that didn't fix it. Any suggestions on what to look for?

 

[disk11]

I decided to open it up. The contacts in the slot appear to be fine, no burn marks or discoloration. Only thing that looks odd is the bigger caps on both the module slot board and some in the back end have a yellow green goo around them. I tried to google some gut shots but came up empty. I would post pics, but my camera is on loan at the moment.