User Guide

PAMS
Technical Documentation
NHD–4
Disassembly & Troubleshooting
Page 24
Original 11/97
Troubleshooting Diagram; Power Up Malfunction
Start
clock running
OK?
1. MCU
1.1 VCTCXO
running OK?
1.2 Clock signal
at CDRFI (N700)
pin 63 ?
1.22 Check connections
between D706 and D704
2. MCU’s
supply voltages
OK?
3. MCU
reset signal OK?
5. All supply
voltages OK?
6. FLASH line
OK?
1.11 Check
VCO_EN is 3V
2.1 Check PSL+(N500)
VL1–line at pin 4
3.1 Is N500
XPWR_RESET signal
OK?
3.11 Check
PSL+(N500)
pins 10
and 12
3.12 Check connections
between D706, D704 and
Do flashing again
YES
NO
NO
NO
YES
YES
NO
YES
YES
YES
YES
YES
NO
NO
NO
Check
corresponding
component
NO
especially clock signals.
If they are OK replace
1.12 Check
Vctcxo sine wave
and VRXS is
4.5V, if OK
replace CDCONT
(N201)
D704
if OK replace
PSL+(N500)
N500. If OK replace D704
Check solder
joints, if OK
replace
CDRFI
(N700)
Power up
OK!
4. Is 32KHz
clock running
4.1 Check D704 pins 36,
37,46,125. Also check
YES
NO
OK ?
B700, C744, C745, R837.,
replace B700. If problem
persists replace D704
R757. If they are OK