User Guide

PAMS
Technical Documentation
RAE-3
8. Troubleshooting
Page 8 – 33
Issue 1 06/01
2.9.3 CMT display backlight blinking 3 times in a loop
CMT display backlight blinking 3 times in a loop (”SDRAM fault”):
D350 SDRAM test fails
Check activity from SDRAM lilnes
Pulses on MADLinda control lines J312, J313, J314,
J310, J348, J315, J316 or J349
D300 faulty
NO
OK
Replace D350 if J349
data pulses with big
overshoot spikes are
missing
SDRRASX (J312): negative pulses (2.8V) SDRCASX (J313): negative pulses (2.8V)
SDRAd6 (J348): postive pulses (2.8V) SDRDQML (J315): negative pulses (2.8V)
SDRWEX (J314): negative pulses(2.8V) SDRCLK (J310): 13MHz clock (2.8V)
SDRDQMU (J316): negative pulses (2.8V) SDRCKE (J311): high (2.8V)
SDRDa8 (J349): positive pulses (data pulses driven by SDRAM have bigger
over shoot spikes than data driven by MADLinda MCU, see figure 23) (2.8V)
Figure 21.