Nihon Kohden BSM-4113K Patient Monitor Wiring Cable for Keypad, High Voltage Board, Alarm Indicator Board and Mainboard

Wiring for Nihon Kohden BSM-4113K 

Nihon Kohden BSM-4113K Patient Monitor Wiring Cable for Keypad, High Voltage Board, Alarm Indicator Board and Mainboard

► Brief Description

The Nihon Kohden BSM-4113K is a classic bedside monitor. This wiring section connects the keypad, high-voltage board, alarm indicator board, and mainboard, and is crucial for resolving issues such as black screens, malfunctioning buttons, or abnormal alarms. The following is a description of each circuit board:

• High-voltage board: Responsible for converting low-voltage DC to high-voltage AC power required for the LCD screen backlight.
• Keypad board: Processes user input commands and transmits signals to the mainboard.
• Alarm indicator board: Receives alarm signals from the mainboard and controls the flashing of the lights.

► Cable Wiring

High Voltage Board Wiring:

The high-voltage board is a component with a high failure rate in monitors. Common problems include a black screen upon startup or a flickering screen. In the BSM-4113K or similar models, the wiring of the high-voltage board mainly involves three core parts: power input, ground wire, and backlight switch control signal. Please be extremely careful when the board malfunctions to avoid affecting its performance or endangering your own safety due to high voltage.

Keyboard Wiring:

The keyboard board not only transmits key signals, but some designs also power the keyboard backlight via the same ribbon cable. In case of a malfunction, check if the ribbon cable is oxidized or broken, or confirm that the latches on the ribbon cable connector (ZIF connector) are securely fastened.

Alarm Indicator Board Cable Wiring:

The main function of this circuit board is for visual alarms, and it is located on the top of the monitor. The wiring structure is relatively simple; it is typically powered by a 5V or 3.3V mainboard and receives high and low voltage levels via signal lines to drive LEDs. If the alarm sound is normal but the light does not illuminate, check if the ribbon cable connecting to the board is loose or if the LED is burnt out.

► Note

If you need to replace the Nihon Kohden BSM-4113K Patient Monitor Wiring Cable for Keypad, High Voltage Board, Alarm Indicator Board, and Mainboard, please pay attention to the following:

• Power Off Operation: Before plugging or unplugging any internal wiring, always disconnect the monitor's power cord and battery, and wait a few minutes for the capacitors to discharge.
• Electrostatic Discharge Protection: When handling the motherboard and chip pins, wear an anti-static wrist strap to prevent electrostatic discharge from damaging sensitive components.
• Insulation Treatment: When repairing the high-voltage board, ensure proper insulation to prevent high-voltage breakdown or short circuits.