Motorola ASTRO XTS 5000 Detailed Service Manual page 98

5-20
VOCON TX Audio—Page 2
Use an oscilloscope to check the
SSI audio signals from the GCAP
(U703). The following test points
are used for data collection:
DCLK: 520 kHz Square Wave Clock*
256 kHz Square Wave Clock**
TX: Audio Data Words
SYNC: 8 kHz Frame Sync Pulse
and Frame Sync
present?
present at TX
test point?
flowchart
July 21, 2004
1
* on NTN9564, NNTN4563 & NNTN4819 VOCON boards
** on NNTN4717 VOCON board
Clock Replace U301*
No
Replace U401**
(Flipper ASIC)
Yes
Data
No
Replace U501
(GCAP II)
Yes
Go to
TX RF
2
Replace
U509
(EEPOT)
Troubleshooting Charts: VOCON TX Audio—Page 1
* on NTN9564, NNTN4563 & NNTN4819 VOCON boards
** on NNTN4717 VOCON board
No
Problem
Resolved?
Yes
End
Is
1 kHz signal
No
present at about
14 mV
rms?
Yes
Problem Yes
Solved?
No
1
Replace
U501
(GCAP II)
End
MAEPF-27397-A
6881094C31-D