Sam4s ER-600, Руководство по обслуживанию

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7 Troubleshooting
7-2 SAM4S ER-600 SERIES
7-2 System Problem
End
System Problem
Reset Signal
Ok?
Y
N
1. Check the IC M51953B(U17).
2. Check the RST Pattern on PCB.
Power Fail
Signal Ok?
Program
Ok?
Y
1. Check the nCS, nRD signal of Flash ROM
2. Check the Addr/Data line Pattern whether it is short.
3. Download the PGM File in Flash ROM through RS-232
Cable.
4. Replace the Flash ROM
1. Check the LM393(U15)
2. Check the Power (+24V,+5V)
3. Check the related Circuit and Pattern on PCB.
N
N
SRAM Ok?
Y
Y
N
CPU
Ok?
Y
N
1. Check the nCS, nRD, nWR signal of SRAM
2. Check the VBT(Battery Volt.).
3. Check the Decoder IC 74HC138 (U9).
4. Replace the SRAM.
Y
N
1. Check the Clock (14.7456MHz)
2. Check the Power of CPU VCC Pin (+5V)
3. Check the mounted state of CPU pin whether the pin is
open or short
RTC Ok?
1. Check the VBT(Battery Volt.).
2. Check the RTC Clock 32.768KHz
3. Replace the RTC(RS5C372A)