Chart 6. 01/81 Host Rom Checksum Failure - Motorola ASTRO Digital Saber Service Manual

DC Supply Failure
This failure implies a problem
with the DC power distribution.
It may relate to a battery
supply or one of the regulated
Connect supply or
supplies. Basic failure modes
battery (B+) to radio
are as follows:
and turn
1) Fuse S1 blown.
ON/OFF/VOLUME
2) Open in Battery contacts or
CONTROL knob on.
from flex circuit through J401.
3) Defective switch Q207.
4) Open in B+_SENSE through
control top switch or
B+_SENSE not detected by µC.
Yes
No Is B+ at
5) Defective +5V regulator.
Q207-2?
Verify B+ at
Check fuse S1.
Q207-5.
No
No
Is B+ at
Fuse good? Replace fuse.
Q207-5?
Yes
Yes
Locate and repair
Check inverter
open between
No
circuit of Q206
Is +5VDC ± 5%
battery and VOCON
and R244.
board.
at C470?
Verify Lx signal per
Yes
Fig. W1.
Verify integrity of Yes
CR403, C470, C463 U409 running?
and R436.
Is the
Yes
output on
U202
+5VDC?
No
No
Verify SW_B+
Verify U409-2
at input to
> 2VDC.
U202 and
RESET signal is
logic low.
Check
U409
continuity of No
switched
B+SENSE to
on?
U409 and R423 Yes
Signals
pull-up.
verified?
Yes
Verify L402 continuity
No
< 1 Ω and solder
connection to board.
Repair connections
back to the vocon
board through J401.
No
Replace L402. L402 good?
Replace U202.
Yes
Replace U409.
Chart 5 . DC Supply Failure
Synopsis
Verify control
voltage at
Q207-4 is logic
low.
No
Control voltage
correct?
Yes
Replace Q207.
Is the
Yes
output on
End
U410-3
+5VDC?
No
Verify SW_B+
at input to
U410.
Yes
Signals
verified?
No
Repair connections .
Replace U410.
MAEPF-24399-O
Fail 01/81
Host ROM Checksum
Failure
Visually inspect all
leads to U205 and
U210 with a 5x glass.
No
Connections
Repair opens.
good?
Yes
Use ohmmeter to electrically
verify following signal
connections to source IC:
Signal @ U205/U210 Source
HD0-HD7 U204
HA0-HA13 U204
HA14OUT,HA15OUT U206
HA16,HA17 U206
ROMCS1*,ROMCS2* U206
OE*,MEMR/W* U206
VCC +5V
VSS GND
No
Connections
Repair opens.
good?
Yes
ReFLASH Host
ROM
Host ROM No
ReFLASH
passed?
Yes
End
Chart 6 . 01/81 Host ROM Checksum Failure
Synopsis
This failure indicates the Host
ROM program code is incorrect.
It is implied that the host
processor found and executed
enough valid code at power up
to get to the point of verifying
the rest. Basic failure modes
are as follows:
1) The contents of U205/U210
have been corrupted.
2) The decoding logic comprised
of U204 and U206 is not
working properly due possibly
to circuit opens or shorts or
that a failure of one or more of
these ICs has occurred.
3) U205 or U210 has failed.
Due to the fact that the Host µC
successfully initialized, a
failure in one of the ICs is not
likely.
Replace
U205/U210. Yes
Initial
Check for operation of
operation
U204 and U206 as
checks
follows: During radio
Good?
power up Self-Test,
verify activity
(transisitons from high
No
to low) on U205/U210 -
ROM1CS*/ROM2CS*,
Refer to section on
and OE*.
Power-up Failure C.3
and/or Fails to
Bootstrap C.4.
MAEPF-24421-A
10-5