akira CT-14CQS5CPT, Service Manual

Page: 17 / 44

Model no.:CT-21CQS5CPT.doc
version 1.0
17
2.2 Confirmation and Adjustment for Voltage
Caution:
+B voltage has close relation to high voltage. To prevent X-ray radiation, set +B
voltage to the rated value
•Make sure that the supply voltage is within the range of the rated value.
•Connect a digital voltmeter to the voltage output terminal of the main PCB. Power on the
TV and set the brightness and sub-brightness to minimum. Ensure that the voltage from
the main PCB reads as follows.
•Regulate voltage adjustment components on the power section until the +B the voltage
reaches the rated value.
Table 1
Test Point Voltage Test Point Voltage
TP-115V 117V±1.5V TP-18V 23V±2V
TP-15V 15.5V±1V TP-5V 5V±0.5V
TP-3.3V 3.3V±0.3V TP-8V 8V±1V
TP-12V 13V±2V TP--12V -13V±2V
TP-195V 196V±2V
Note:
It’s impossible to check the power part separately from the main chassis board as
the part is mounted on the main chassis board. The power components, etc. should be
checked for burnout when power-on. If burned out, do not power on the TV again until the
cause is found out.
2.3 High Voltage Inspection
Measure voltages of test points on the main PCB with the digital voltmeter. Measure the
CRT high voltage with the high-voltage testing equipment and heater voltage with the
high-frequency effective voltmeter. The rated values are shown as below.
Table 2
Test Point Voltage Test Point Voltage
Negative of VD49 1 1 96±2V 14"GS_CRT_anode 22±1.5KV
21 "FS_CRT_anode 26±1.5KV 21 "PF-CRT-anode 27±1.5KV
Heater 6.3±0.3Vrms
2.4 Focus Adjustment
Caution:
Dangerously high voltages are present inside the TV. Extreme caution
should be exercised when working on the TV with the back removed.
•After removing the back cover, look for the FBT on the main PCB. There should be a
FCB (FOCUS) on the FBT.
•Power on the TV and preheat it for 15 min.
•Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture