What was found
THE FSS DISCHARGE LIGHT ILLUMINATED WITH NO OTHER INDICATIONS IN THE COCKPIT. THE FSS CONTROL PANEL SHOWED SUPPRESSING FIRE WITH A FAULT ILLUMINATED IN POS 2R. THE FAULT ALSO SHOWED BURST DISK. TEMP WINDOW ALSO SHOWED MANY TEMP VARIATIONS BETWEEN -4 TO 500 DEG. RAN FSS DISCHARGE LIGHT CHECKLIST, & THE FIRE CARGO CHECKLIST. ITEMS ACCOMPLISHED & ACFT DIVERTED. ON VISUAL INSPECTION, FSS NOZZLE POSITIONED ITSELF OVER THE CAN IN POS 2R, BUT DID NOT PENETRATE. FIRE SUPPRESSION FOAM DID EXIT THE NOZZLE & SPEWED ALL OVER. ACTIVATION STEPS COMPLIED WITH IAW MM 26-20-10.