Function Dial Board UR-3544 6190-019704A for Nihon Kohden BSM-4113K Patient Monitor

Function Dial Board UR-3544

Function Dial Board UR-3544 6190-019704A for Nihon Kohden BSM-4113K Patient Monitor

► Brief Description

The Function Dial Board UR-3544 is a core component of the Nihon Kohden BSM-4113K Patient Monitor's operation and control system. It is the input circuit board responsible for processing signals from the function knobs and related buttons. Within the BSM-4113K monitor's hardware architecture, it plays a crucial role as the Human-Machine Interface (HMI).

The board's core function is to convert physical rotation and button clicks into digital signals, transmitting them to the mainboard CPU to enable navigation of on-screen menus, adjustment of alarm limits, and parameter configuration.

► Technical Functions

Although the UR-3544 circuit board is small in size, its stability directly impacts the user experience for medical staff. Its technical functions mainly include the following:

1. Rotary Encoder Signal Processing: An onboard high-precision rotary encoder captures the clockwise/counterclockwise rotation of the main knob. This signal is used to move the cursor and increment/decrement values on the monitor screen.
2. Key Matrix Scanning: In addition to the knob, the board integrates scanning circuitry for the shortcut function keys distributed around it.
3. Signal Debouncing and Transmission: Through an onboard microcontroller or logic circuit, mechanical vibrations caused by physical contact are filtered to ensure the accuracy of input commands. Clean digital signals are then transmitted to the main control board via ribbon cables.

► Common Faults

• 1. Knob Malfunction/Jittering: May be due to wear or oxidation of the rotary encoder.

Solution: The screen value jumps erratically when rotating the knob, or requires repeated rotation to produce a response. Clean or replace the UR-3544 board.

• 2. Some Buttons Unresponsive: May be due to a damaged microswitch or aging conductive adhesive.

Solution: Pressing a specific key (such as "Silence") yields no feedback. Check the onboard switch continuity.

• 3. Control Panel Unresponsive: May be due to a loose ribbon cable or onboard power supply failure.

Solution: The entire panel freezes. Check if the ribbon cable connecting to the motherboard is loose, or measure the onboard voltage.

• 4. Button Sticking/Repeated Clicking: May be due to liquid seepage causing a short circuit.

Solution: History of disinfectant or liquid splashes. Check the circuit board for corrosion.

► Note

When this board malfunctions and needs replacement or repair, please pay attention to the following:

• Electrostatic Discharge Protection: The UR-3544 is a precision electronic component. An anti-static wrist strap must be worn during disassembly and installation to prevent electrostatic discharge from damaging the onboard chips.
• Caliper Handling: The flexible flat cable connecting the UR-3544 is very fragile. Handle the clips carefully during disassembly to avoid breaking the cable, which could lead to poor contact.
• Calibration Testing: After replacing the board, it is recommended to enter service mode or perform routine functional tests to ensure the knobs are sensitive and all buttons function correctly, without any "double-clicking" phenomenon.