Motorola ASTRO MT 1500, Service Manual

Page: 175 / 817

6816985H01-B August 16, 2007
VHF Troubleshooting Charts: Zone/Channel Select Error Troubleshooting Chart 6.1-11
6.1.12Zone/Channel Select Error Troubleshooting Chart
MAEPF-27337-O
Replace
Switch
S500
Verify
contact with
circuit board
S500
checks
good?
Verify operation
of zone knob per
"Button Test"
flow chart
Signals
check good
at 800?
Verify codeplug
programming with
RSS. If codeplug
checks OK, then
replace U800.
By studying the
adjacent chart against
the channel numbers
which have errors,
one signal may be
determined to be in
error or verify logic
levels at R513-R516
for each channel.
Channel
Select Error
No
No
Yes
Yes
RTA3
(R513)
RTA2
(R514)
RTA1
(R515)
RTA0
(R516)
Channel
Probe Point
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0 1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Verify voltage levels
directly at pin C1 of
the frequency switch
(S500). Position A =
2.2V, Position B = 0V,
Position C = 1.5V