System Problem - Sam4s NR-500R Service Manual

8 Troubleshooting

8-2 System Problem

System Problem
Reset Signal
Ok?
Power Fail
Signal Ok?
CPU
Ok?
Program run
Ok?
SRAM Ok?
RTC Ok?
End
8-2
N
Y
N
Y
N
Y
N
Y
N
Y
N
Y
3. Check the IC AME8500AEET(U13)
4. Check the /RESET Signal Pattern on PCB.
1. Check the LM393(U10)
2. Check the Power (VPRT, VDD3.3V)
3. Check the related Circuit and Pattern on PCB
1. Check the Clock 12MHz(X1)
2. Check the Power of CPU VCC Pin (VDD3.3V)
3. Check the mounted state of CPU pin whether the pin is
open or short
1. Try the Download S/W
2. Check the Addr/Data line Pattern whether it is short.
3. Replace the CPU
1. Check the nCS, nRD, nWR signal of SRAM
2. Check the VBT(Battery Voltage).
3. Check the TR(Q27,Q28;2222) on Main PBA
4. Replace the SRAM.
1. Check the VBT(Battery Voltage).
2. Check the RTC Clock 32.768KHz (X3)
3. Replace the X-TAL
4. Replace the RTC Chip (U31)
SAM4S NR-500 SERIES