What was found
WHILE ON DESCENT, RECEIVED A CHECK FIRE DETECTION WARNING LIGHT. THE APU BOTTLE LOW LIGHT FLICKERED. RESET THE MASTER WARNING LIGHT. THE CHECK FIRE DETECTION WARNING LIGHT EXTINGUISHED. AFTER A FEW SECONDS THE CHECK FIRE DETECTION WARNING LIGHT AGAIN FLASHED ALONG WITH THE MASTER WARNING LIGHT. THIS OCCURED ENTIRE FLIGHT. REPLACED FIRE CONTROL AMPLIFER IAW AMM TASK 26-10-01-00-801 AND 26-10-01-400-801. OPS CHECKED GOOD. RETURNED TO SERVICE.