| Issue | User Manual Solution | Service Manual Solution | | :--- | :--- | :--- | | "No Depth Reading" | Check transducer cable connection. | Use oscilloscope to check 200kHz return pulse at J6 connector; test capacitor C47 on the analog board. | | "Unit won't power on" | Check fuse. | Test MOSFET Q12 for source-drain short; measure 5V_Standby rail on the main regulator. | | "Screen flickers" | Adjust brightness. | Replace CCFL inverter or test LED backlight driver IC (U9). | | "Buttons double click" | Reset to factory defaults. | Desolder the tact switch, clean carbon pads, or replace the microswitch (Omron B3F-xxxx equivalent). |
The most common sources for this technical documentation include: samyung srg 1150 service manual.pdf