Motorola ASTRO XTSTM 4000, Detailed Service Manual

Page: 92 / 210

May 28, 2008 6871620L01-C
5-30 Troubleshooting Charts: Secure Hardware Failure
5.15 Secure Hardware Failure
Yes
No
Yes
No
No
No
Fail
09/10 or 09/90
Secure Hardware
Failure
Connections
good?
Repair
connections
Yes
Replace
secure
module
Verify electrical activity
at the following signals
at power up:
Connections
good?
Repair
opens
No
Yes
Is
known good
module
available?
Replace module
with known good
one and retest
Verify connections
to secure module
through J2
Signals
good?
Yes
Replace
secure
module
Radio
functions with
known good
module?
Replace
Mainboard
This failure relates 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
section at connector J2.
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 J2.
Synopsis
Use ohmmeter to electrically
verify the following signal
connections to source IC:
Signal @ J2 Source
ENC_SSI_DI R1338
ENC_SSI_DO R1337
ENC_SSI_CLK R1335
RESET_ENC R1406
Verify bias of following signals:
Signal @ J701 Nominal Bias
FU_B+ 7.5VDC+/-1.0VDC
SW_B+ 7.5VDC+/-1.0VDC
GND GND
Signal @ J701 Source
ENC_SSI_DI R1338
ENC_SSI_CLK R1335