TIMS showed Fire Internal at Front DT car. Staff (CTH & BGS) checked and confirmed no abnormalities.Staff escorted the train to TNM1. ~~~~~ TIMS showed Fire Internal at Front DT ca  N  Checked FC-720 Smoke internal. Checked 3620 and confirmed no internal smoke alarm activated. Cleaned up 3620 both end internal smoke sensor. Checked 3620 control unit - no sign of water ingress. Monitored for 30mins no fault occurrence. N.A/lai mk/alif/22.05.23