General Hardware Failure - Motorola ASTRO Digital Spectra Plus Service Manual

Troubleshooting Charts
Fail 01/90

General Hardware Failure

Check
No
Command Board for
Command
9.6 V and 5.0 VDC.
Yes
Replace
VOCON
Board.
Yes
Problem
troubleshooting
corrected?
for VOCON.
No
Is there
No
activity on BUSY, RX DATA,
Command
and TX DATA lines?
Yes
Replace
Control
Head.
MAEPF-25209-O
Chart C.5 01/90, General Hardware Failure
6881076C25-D
Replace
Board.
Go to
Replace
Board.
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
Check for operation of
U204 and U206 as
Host ROM No
follows: During radio
ReFLASH
power up Self-Test,
passed?
verify activity
(transitions from high
to low) on U205/U210 -
Yes
ROM1CS*/ROM2CS*,
and OE*.
End
Chart C.6 01/81, Host ROM Checksum Failure
5-7
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 C
successfully initialized, a
failure in one of the ICs is not
likely.
Replace
U205/U210. Yes
Initial
operation
checks
Good?
No
Refer to section on
Power-up Failure C.3
and/or Fails to
Bootstrap C.4.
MAEPF-24421-A
October 28, 2002