York 025-43893-000 Circuit Board

Troubleshooting steps
1. Power-related
Power LED (red light on IPU-II board) does not light up → First, confirm if the input voltage (12 VDC / 24 VAC / 110 VAC / 220 VAC) has been delivered, and check the fuses and connections; if the power supply is confirmed to be correct but the LED still does not light up, it is determined that the board card is damaged and needs to be replaced.
STATUS light is always off but the power LED is on → Usually, it is due to the loss or mismatch of application files (CNF), and it is necessary to re-download the application; if ineffective, replace the gateway board.
2. STATUS light flashes twice (communication loss with the unit)
Confirm that the unit control cabinet has been powered on and is operating normally;
Check if the APP Group A dip switch has called the correct Quick Start (equipment standard) setting;
Check the Port 2 connection, pay special attention to whether RX/TX is reversed, and whether the RS-232 / RS-485 jumper JP27 settings are correct;
Check the unit side: YORK Talk II address (rotate the Micro Panel switch to 0 to set the address 1), and check if the unit is in remote operation mode (Remote) to receive gateway instructions.
3. STATUS light flashes three times (configuration error)
First, power off and restart the gateway; if still not working, re-download (XMODEM) the application CNF file; if still cannot be restored, replace the board card.