Changhong Electric 34T18, Service Manual, Page: 10 / 61

SERVICE MANUAL
8
Positive of C434 13.5V
±
1V
Positive of C840 8V
±
0.5V
One Pin of 326 12V
±
1V
Positive of C424 5V ± 0.5V
Heater 6.3V ± 0.3Vrms
CRT anode voltages
29KV ± 1.5KV (For 29” CRT)
31.0KV ± 1.5KV (For 34” CRT)
3. High Voltage Inspection
Caution: No high voltage adjustment components inside the chassis. Please perform
high voltage inspection in the following ways.
3.1 Connect a precise static high voltmeter to the second anode (inside the high voltage cap) of the
CRT.
3.2 Plug in the supply socket (220V ~, 50Hz) and turn on the TV. Set the brightness and contrast to
minimum (0 μ A).
3.3 The high voltage reading should be less than the limited EHT voltage.
3.4 Change the brightness from minimum to maximum, and ensure high voltage not beyond the
limitation in any case.
Nominal EHT voltage Limited EHT voltage Remarks
29KV ± 1.5KV 33KV for 29" CRT
31.0KV
±
1.5KV 35KV for 34" CRT
Note: The data sheet may differ dependent on different CRTs.
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.
4.1 After removing the back cover, look for the FBT on the main PCB. There should be a FCB on
the FBT.
4.2 Power on the TV and preheat it for 15 min.
4.3 Receive a normal TV signal. Rotate knob of the FCB until you get a sharp picture.
Before Adjusting After Adjusting
Fig. 4