Sony KD-34XBR2 Training Manual page 86

9. Place your scope at Q6009/Drain of the primary power supply. Gradually increase the Variac voltage. The
square Waveform 19-1 will start at 16Vac and gradually increase in amplitude. Make sure the waveform is flat
on the top and bottom and its Vp-p is at the same level as the DC voltage from main rectifier D6001. For
example at 20Vac, there is 60Vdc from D6001 and waveform should be 60Vp-p. Waveform 1 shows the
square shape at 20Vac input to the TV.
PM3394, FLUKE & PHILIPS
ch1: pkpk= 57.6 V
ch1: freq= 220kHz
1
T
CH1!10.0 V~ MTB1.00us
Waveform 19-1 - Primary PS Output – 20Vac
Name
Channel 1 IC6002
Output
Time base
Waveform frequency = 220kHz
10. Stop at each AC input level to recheck the output voltage and verify that almost no AC current is drawn. Only
the primary PS voltages in Chart 19-2 will output. The frequency of the primary oscillator should remain at
220kHz as the input voltage increases because the regulator circuit has been disabled (step 2).
11. Finally, test the regulating circuit by measuring the voltage across PH6005/pins 1-2 with the board powered
up. 0V = normal. 1.2V or higher means the regulating IC6107 is defective.
Chart 19-2 – Primary and Secondary Output Voltages at various input voltages
AC Input Voltage
D6001 Output
Primary PS
CN6104/pin 1 (11V)
CN6104/pin 2 (7V)
CN6104/pin 8 (6.5V)
Secondary PS
CN6106/pin 9 (135V)
CN6106/pin 6 & 4 (+22V)
CN6106/pin 3 & 1 (+15V)
Running both the Primary and Secondary Power Supply
12. Unplug the AC and disconnect the DC voltage to the blocking diode.
13. Move the resistor and diode from IC6002/pins 1 and 7 to IC6001/pins 1 and 7.
14. Short Q6003/ base to emitter. This enables IC6001.
15. Move the short from across PH6005/pins 3-4 to PH6002/pins 3-4.
16. Place the scope probe at Q6007/Source to monitor the oscillator output.
17. Connect the DC power supply to the blocking diode that is soldered to IC6001/pin 7.
ch1-
input
Location Voltage/div
Q6009/Drain 57Vp-p
1usec/div
20Vac
60Vdc
1.86Vdc
1.1Vdc
0.72Vdc
18.55Vdc
+3Vdc
+2Vdc
19. Projection TV RA-5A Chassis Power Supply Board Tests
PH6005
PH6002
Sec PS
IC6001
Q6003
30Vac 50Vac
87Vdc 146Vdc
2.38Vdc 4.1Vdc
1.55Vdc 2.7Vdc
1.1Vdc 1.96Vdc
25.3Vdc 44.4Vdc
+4.16Vdc +7.6Vdc
+2.8Vdc +5Vdc
83
Figure 19-1
CN6106 CN6101 CN6102 CN6104
G Board - RA-5a Chassis
Bottom view
1
1
Prim PS IC6002
90Vac
254Vdc
6.24Vdc
4.6Vdc
3.5Vdc
79Vdc
+13.46Vdc
+8.8Vdc
Q6009
RY6001
120Vac
336Vdc
7.8Vdc
5.8Vdc
4.6Vdc
108Vdc
+18.3Vdc
+12Vdc