Sam4s SPS-500 SERIES Service Manual page 91

6 Troubleshooting
6-6 LCD B'D Problem (Boot, LCD Panel, Touch Panel, Rear LCD, LED)
6-6-1 LCD B'D Boot problem
 Related RESET
→ Check the harness between Dallas-Key and IO B'D, if it is connected or not.
→ Check the reset signal of 74HC08 (U1) output.
 Related Program
→ The micom(ATMEGA8, U5) has the internal flash to store the program.
→ Check the program is broken or erased.
 Related System Clock
→ Check the crystal, if it operates correctly or not.
→ Clock frequency is 14.7456MHz.
6-6-2 LCD Panel problem
 Operation Fail
→ Performs the LCD panel test at H/W test mode.
→ Check the power voltage (VDD3.3V) on LCD B'D.
→ Check the FFC harness between LCD panel to LCD B'D.
→ Check related circuit & component whether short or not.
→ Check the micom on LCD B'D whether it works normally or dead.
→ Check the harness between LCD B'D and IO B'D, if communication is OK or not.
→ Check the connection. between MAIN B'D and IO B'D, if communication is OK or not.
6-6-3 Touch panel problem
 Operation Fail
→ Performs the touch panel test at H/W test mode.
→ Check the FPC harness between touch panel to LCD B'D.
→ Check related circuit & component whether short or not.
→ Check the harness between LCD B'D and IO B'D, if communication is OK or not.
→ Check the connection. between MAIN B'D and IO B'D, if communication is OK or not.
6-6-4 Rear LCD problem
 Operation Fail
→ Performs the Rear LCD test at H/W test mode.
→ Check the harness between Rear LCD to LCD B'D.
→ Check related circuit & component whether short or not.
6-6-5 LED B'D problem
 Operation Fail
→ Performs the LED test at H/W test mode.
→ Check the harness between LED B'D to LCD B'D.
→ Check related circuit & component whether short or not.
6-6 SAM4S SPS-500 SERIES