What was found
INBOUND TO CAK, THE CREW RECEIVED A CAUTION MESSAGE FOR SPOILERONS OB AND OB FLT SPOILERS, SO THEY DECLARED AN EMERGENCY WITH ATC. MX HAS BEEN NOTIFIED, AND THEY REQUESTED TO SWAP THE RETURN TRIP ONTO A DIFFERENT AIRCRAFT SO THEY COULD TROUBLESHOOT THIS ISSUE. THIS FLIGHT HAS LANDED SAFE AND BLOCKED IN. NO FURTHER INFORMATION AT THIS TIME. OB FLT SPLRS CAUTION MESSAGE IN FLIGHT / LH OB FLT SPOILER PCU WAS REPLACED. INSTALLED LH OB FLT SPOILER PCU PER CRJ700 AMM 27-62-01-400-801-A01-PSA UP TO STEP 4A37. C/W CRJ 700 AMM 27-62-01-400-801-PSA THROUGH CLOSE OUT. OPS CHECK AND LEAK CHECK GOOD.OPS CHECK AND LEAK CHECK GOOD IAW CRJ 700 AMM 27-62-01-400-801-PSA."