Codan NGT 2010 RF User Manual

NRI—Fault finding
282 NGT Transceiver System Technical Service Manual
Table 9: Test points on the NRI Vocoder PCB
Test point Description Acceptable
signal/level
Possible fault causes Action
+10 V Regulated +10 V
supply rail from NRI
Microcontroller PCB
+10.0 V ±0.1 V Failed connection Check condition of
J1, and P206 on
NRI
Microcontroller
PCB
Failed +10 V supply
on NRI
Microcontroller PCB
See Table 8
TP17 Charge-pump
generated negative
supply rail
–7.0 V ±0.5 V Failed charge-pump
component
Replace PCB
Failed –5 V regulator Replace PCB
Failed CoDec Replace PCB
–5 V Regulated –5 V rail
generated from above
–5.0 V ±0.1 V Failed voltage
regulator
Replace PCB
Failed CoDec Replace PCB
TP7 Internally multiplied
clock signal
40 MHz ±500 Hz
5 V p–p square wave
Failed connection Check condition of
J1, and P206 on
NRI
Microcontroller
PCB
Failed CT8020 Replace PCB
TP13 SRAM Read Signal Normally logic high
with fast low pulses
Failed CT8020 Replace PCB
Failed RAM IC Replace PCB
TP14 SRAM Write Signal Normally logic high
with fast low pulses
Failed CT8020 Replace PCB
Failed RAM IC Replace PCB
TP15 SRAM Chip Select
Signal
Normally logic high
with fast low pulses
Failed CT8020 Replace PCB
Failed RAM IC Replace PCB
TP3 Codec Clock Signal 2 MHz ±100 Hz
5 V p–p square wave
Failed CT8020 Replace PCB
Failed Codec Replace PCB

Codan NGT 2010 RF Specifications

General

Brand	Codan
Model	NGT 2010 RF
Category	Transceiver
Language	English