(1) to adjust the brightness, to see whether the change.

(2) the multimeter to measure output voltage inverter voltage value with the same model for comparison.

(3) the measured not power amp tube work state and Experience.

(4) VC97 multimeter measured not level efficacy tube operating frequency (10MHZ).

(5) replacement method (lamp).

(6) using analog multimeter 1000V AC file, the red pen then into the high-pressure outlet, if any discharge sound, exemplified by the inverter is normal, and high pressure measuring pen measurement available, but to pay attention to their personal security.

(7) the measuring current law: Disconnect insurance, measurement should be about 400mA-1A current, if the current is very small, indicating that the Screen Inverter is not working properly. If the output voltage is low:

a power supply voltage is low.

transformers serious short circuit.

c. IC bad.

d. external timing components.

e. voltage stability and overvoltage circuit damage.

(8) multimeter table pen gradually close to the high voltage output, to see whether the arcing.

(9) measured with an oscilloscope final stage amplifier tube, to see whether the more than 20 volts, so the waveform 50KHZ if waveform Compaq Presario CQ61-407SF Inverter normal.