Sam4s ER-900 Series, Руководство по обслуживанию

Страница: 40 / 132

6 Troubleshooting
6-2 SAM4S ER-900/SPS-300 SERIES
6-3 MAIN B’D Problem (System boot & program)
6-3-1 PGM Flash ROM (A29L1600UV) problem of Main B’D
„
Related RESET
→ Check the reset IC (AME8500, U5) & reset time (150 ~ 270ms)..
→ Check related circuit & component whether short or not
„
Related System signals (Address, Data, nCE, nOE, nWE)
→ Check these signals whether it short / open.
„
Related System Clock
→ Check the crystal, if it operates correctly or not.
→ Clock frequency is 12MHz.
„
Related PGM Flash ROM program (A29L1600UV)
→ If the boot program is erased during servicing, boot error is occurred.
→ You should replace the flash ROM with programmed new flash ROM.
6-4 MAIN B’D Problem (LCD, Rear Display, Data Memory, RTC, Battery)
6-4-1 Back-light of LCD problem
„ Check the back-light voltage (VDD5V) on LCD Joint B’D.
„ Check harness
→ Harness between Main B’D and LCD Joint B’D (22-pin).
→ Harness between LCD Module and LCD Joint B’D (wire harness 22-pin or 16-pin).
„ Check the signal (Back-light on/off signal)
→ Check this signal whether it short / open.
6-4-2 Display of LCD problem
„ Check the LCD TTL signals on Main B’D.
→ Check the reset signal of AME8500 (U5) output.
→ Check the MCU(LPC2470, U6) and the transceiver (74ACT245, U13) output LCD signals
(R/W and CE#1~#3, EN, data, D/I, etc.)
→ Measure these signals and check whether it short/open or not
„ Check harness.
→ Harness between Main B’D and LCD Joint B’D (22-pin).
→ Harness between LCD Module and LCD Joint B’D (Wire harness 22-pin or 16-pin).
„ Check the voltage VDD50V on the LCD Joint B’D. This voltage is used for LCD Module logic.
6-4-3 Rear Display(FND) problem
„
Operation Fail
→ Performs the Rear Display(FND) test at H/W test mode.
→ Check the harness between Rear Display B’D and LCD Joint B’D. (FFC harness 17-pin).
→ Check the harness between LCD Joint B’D and Main B’D. (Wire harness 18-pin).
→ Check the MCU(LPC2470, U6) output FND signals.(Segments, Digits)
→ Check related circuit & component on the LCD Joint B’D whether short or not.