TIMS showed Fire Internal at car 1553. Staff(AMK) checked and confirmed no signs of fire on exterioror interior of train. Train was escorted by station staff f rom AMK, KTB, SBW, MSL and YWT. ~~~~~ TIMS showed Fire Internal at car 1553. S     #1553 fault code 720x1.Check smoke detector PCB no sign of water ingress.Use air compressor blow,service smoke detector unit and sensor.Functional check ok.Monitor for an hour no sign of fault occurance.To monitor at M/L. Done by Haslan/Zulq  04/06/23