Motorola i897 - Page 85

TROUBLESHOOTING: RF PA Module Test
Tx Janus Module Test (Continued)
A
B
Continued
from previous
Page
Continued
from previous
Page
an
d
Check JANUS U
500
R
708 (
Raw B+
at C
504
voltage
)
The JANUS module is OK
.
Yes
Is
the Power level betwee
n
27
an
d
30
dBm
?
Yes
No
No
No
Do the following
:
1
.
Check JANUS U
500
for ba
d
solder connections
.
2
.
Check for open traces
.
3
.
Check C
692
and
R
759 ,
fo
r
defective components
.
4
.
Check SLEDGEHAMME
R
2
line and perform
a
.
_
JSEL
GP
04
Is
Raw B+ present at C
504
and
R
708
?
No
Do the following
:
1
.
Check JANUS U
500
for ba
d
solder connections
.
2
.
Check for open traces
.
3
.
Check C
504 ,
R
708
E701
an
d
for defective components
.
Yes
Yes
700
.
E
Do the following
:
1
Check JANUS U
500
for ba
d
solder connections
.
2
.
Check for open traces
.
3
.
Check C
505 ,
R
501
for defective components
an
d
Is
V2
_
TX
(2.77 V)
present at C
505
and
R
501
?
Y
es
Is
VCON
(2.77 V)
present at C
692
an
d
R
759
?
Replace the JANUS module
U500
and then perform the TX
.
Do the following
:
1
.
Check JANUS U
500
for ba
d
solder connections
.
2
.
Check for open traces
.
3
.
Perform the
SLEDGEHAMMER Tes
t
Is
TX
_
ENB
(
test point
TP
_
ASW low during the
TX slot
?
?
.
JANUS Module Test again
Do the following
:
1 .
Set the unit to the TX
Power Tune T tes
.
2 .
Set the Power Tune
softpot to max auto pow r e
.
3 .
Measure the RF power
level at the antenna por
t
.
6880401P59-O
85