(No.RA053<Rev.001>)1-163
[Inspection procedure]
[Remarks]
The following things are assumed as causes of trouble besides the above
• PLL data is abnormal
• VCO/PLL lock judgment is abnormal[<IC401>OMAP]
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or
Unlock[Unlock beep / VCO assist tuning is impossible]
Assist Auto Tuning
Auto tuning NG
Assist Manual Tuning
Manual tuning NG
Check the VCO output signal
Signal existence
Observe the signal at point [A] with spectrum analyzer thru high impedance probe
No signal
No short-circuit
Remove <R182><R183><Q181> and check whether it is short circuited at point [A]
Short-circuit
Check the VCO power supply
Measure the voltage at point* [B] or [K]
The checked voltage is
not about from 4 to 5V.
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
point [B]
*In case, Radio frequency is set under 460.05MHz
point [K]
In case, other than those above
The checked voltage is about from 4 to 5V.
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
point [B]
*In case, Radio frequency is set under 460.05MHz
point [K]
In case, other than those above
Remove <R116> or <R117> and measure the voltage at point [B]* or [K]
The checked voltage is
about from 4 to 5V.
The checked voltage is not about from 4 to 5V.
There is a problem outside the BLS. Check the power supply circuit.
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
Check the VCO Assist voltage supply circuit
Measure the voltage at point [C] by setting Assist tuning value [4096]
This voltage fluctuate in conjunction
with the change of Assist tuning value
*When measuring this point, please use a multimeter with sufficiently high input impedance
The checked voltage is about 0V.
The checked voltage is about 0V.
Remove <R108><R109> and measure the voltage at point [J]
*Assist voltage switch<Q102> is on in the state of Assist tuning mode
There is a problem outside the BLS. Check the Assist voltage supply circuit.
In case of tuning value is [4096] , this voltage is about 18.3V
*In case of tuning value is [1] , this voltage is about 0V
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
Observe the signal at point [A] with spectrum analyzer thru high impedance probe
Thissignalfluctuatein conjunction
with the change of the voltage at point[C]
If normal condition,
frequency will be less than 800MHz at assist=1
And frequency will be more than 1040MHz at assist=4096.
Thissignaldoesn't fluctuatein conjunction
with the change of the voltage at point [C]
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
Check the VCO control voltage supply circuit
Measure the voltage at point [D]
*In case of Assist tuning value is [1] , this voltage is about 4.7V
In case of Assist tuning value is [4096] , this voltage is about 0.1V
This voltage fluctuate in conjunction
with the change of Assist tuning value
When the above condition is not satisfied
There is a problem outside the BLS. Check the circuit around IC303.
Remove <IC102> and measure the voltage at point [E]
Thisvoltage difference between
point [D]and point [E]is more than 0.1V
Thisvoltage difference between
point [D]and point [E]is less than 0.1V
There is a problem outside the BLS. Please check the circuit posterior to <IC102>
Please refer to [Remarks] below.
There is a problem with the VCO circuit inside a BLS / Please replace to new PCB
Modulation trouble / Balance tuning is impossible
Check the VCO modulation circuit
Check the FM deviation in a Balance tuning mode at 2kHz sample tone
When FM deviation don't fluctuate in conjunction
with the change of the Balance tuning value
Check the modulation signal at point [ I ] in a Balance tuning mode at 2kHz sample tone
Signal existence[2kHz tone]
*In case of Balance tuning value is [1024], this signal level is about from 1.1[Vp-p] to 1.5[Vp-p]
(1)Remove <R142><Q116> and check the modulation signal at point [F] in a Balance tuning mode at 2kHz sample tone
(2)Remove <R124> and check the modulation signal at point G in a Balance tuning mode at 2kHz sample tone
The modulation signal can be confirmed,
and signal level fluctuate in conjunction with Balance tuning value
There is a problem with the VCO circuit inside a BLS / Please exchange it for a new PCB
(1)
*In case, Radio frequency is set under 460.05MHz
(2)
In case, other than those above
This voltage fluctuate in conjunction
with the change of Assist tuning value