System Problem - Sam4s ER-5200 Service Manual

8 Troubleshooting

8-2 System Problem

System Problem
Reset Signal
Ok?
Y
Power Fail
Signal Ok?
Y
CPU
Ok?
Y
Program
Ok?
Y
SRAM Ok?
Y
RTC Ok?
Y
End
8-2
1. Check the IC M51953B(U13)
N
2. Check the 74HC14(U17).
3. Check the RST Pattern on PCB.
1. Check the LM393(U22)
N
2. Check the Power (+24V,+5V)
3. Check the related Circuit and Pattern on PWB
1. Check the Clock (14.7456MHz)
2. Check the Power of CPU VCC Pin (+5V)
N
3. Check the mounted state of CPU pin whether the pin is
open or short
1. Check the nCS, nRD signal of Flash ROM
2. Check the Addr/Data line Pattern whether it is short.
N
3. Download the PGM File in Flash ROM through RS-232
Cable.
4. Replace the Flash ROM
1. Check the nCS, nRD, nWR signal of SRAM
N
2. Check the VBT(Battery Volt.).
3. Check the Decoder IC 74HC138 (U24).
4. Replace the SRAM.
1. Check the nCS, nRD, nWR signal of RTC
2. Check the VBT(Battery Volt.).
N
3. Check the Decoder IC 74HC138 (U24).
4. Check the RTC Clock 32.768KHz
5. Replace the RTC(RF5C15)
SAM4S ER-5200 Series