Motorola ASTRO XTS 5000 - Page 116

6881094C31-E November 16, 2006
Troubleshooting Charts: VCO TX/RX Unlock 5-25
VOCON TX Audio—Page 2
MAEPF-27397-A
Replace U501
(GCAP II)
Replace
U509
(EEPOT)
Go to
TX RF
flowchart
Replace U301*
(Flipper ASIC)
Clock
and Frame Sync
present?
Data
present at TX
test point?
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*
TX: Audio Data Words
SYNC: 8 kHz Frame Sync Pulse
No
Ye s
Ye s
End
Problem
Resolved?
Ye s
1
2
1
No
No
End
Replace
U501
(GCAP II)
Is
1 kHz signal
present at about
14 mV
rms?
Problem
Solved?
No
Ye s
No
Ye s
256 kHz Square Wave Clock**
* on NTN9564, NNTN4563 & NNTN4819 VOCON boards
** on NNTN4717 VOCON board
* on NTN9564, NNTN4563 & NNTN4819 VOCON board
s
** on NNTN4717 VOCON board
Replace U401**