SARACOM HC 7123 HORN CONTROL PANEL

Kindly be informed that, the AFT horn cannot be activated electrically by the control push buttons in relative panel, but it is operational manually/mechanically at present of time by the available handle. the case was attended and observed some malfunction was happen while the using air horn thru control panel, just the LED of heater was going on and cannot select the air horn by button from control panel, The controller PCB and solenoid valve coil were checked and all relative wires were retighten and also the controller input AC power supply was measured, found normal, then relative resistance of solenoid v/v coil was checked and shows (370 OHM), unfortunately the fault is remained, suspected that the controller has defected, and more investigation is in progress. 

"Kindly advise"

model: saracom hc-7123 horn control unit