User's Manual

6881094C31-C October 14, 2003
Troubleshooting Charts: Secure Hardware Failure 5-35
5.18 Secure Hardware Failure
MAEPF-27387-O
Ye s
No
Ye s
No
No
No
Fail
09/10 or 09/90
Secure Hardware
Failure
Connections
good?
Repair
connections
Ye s
Replace
secure
module
Verify electrical activity
at the following signals
at power up:
Connections
good?
Repair
opens
No
Ye s
Is
known good
module
available?
Replace module
with known good
one and retest
Verify connections
to secure module
through J701
Signals
good?
Ye s
Replace
secure
module
Radio
functions with
known good
module?
Replace
respective
source IC or
VOCON board
This failure relates only to secure-equipped
radios and indicates a power-up self-test failure
for the secure module. More specifically this
failure indicates a failure in communications
between the DSP and secure module. The
secure module is not considered field repairable
so troubleshooting is limited to verifying a
problem with the module and replacing.
Typical failure modes would be:
1) Open between secure module and VOCON
board at J701.
2) Failure of the SSI bus that the DSP uses to
communicate with the secure module.
3) Failure to get proper supplies and grounds
to J701.
Synopsis
Use ohmmeter to electrically
verify the following signal
connections to source IC:
Signal @ J701 Source
ENC_SSI_DI R403
ENC_SSI_DO R402
ENC_SSI_CLK R405
RESET_ENC R418
Verify bias of following signals:
Signal @ J701 Nominal Bias
UNSW_B+ 7.5VDC+/-1.0VDC
SW_B+ 7.5VDC+/-1.0VDC
GND GND
Signal @ J701 Source
ENC_SSI_DI R403
ENC_SSI_CLK R405