Panasonic CF-74GCDADBM service manual Troubleshooting

4.2. Troubleshooting

Please take note of the following two points with regard to troubleshooting:

1.Know-how of diagnosis upon occurrence of heavy troubles, e.g. ‘Set cannot be turned ON’, ‘Set fails to start’, ‘No display on screen’, etc.

2.Explanation of each trouble, mainly symptom of trouble in operation.

●Flow Chart

START

Set cannot be supplied with current. Power lamp fails to light up.

Pay attention to the following points when in pursuit of the cause of a troubleshooting.

1.Peripheral apparatus connected with the set should all be removed before operation check.

2.Make sure that cables, boards, etc. are not coming off, and recheck the contact condition.

AC	NG
Adaptor/Battery		Replace AC Adaptor/Battery
Output voltage

OK

Dark display on screen. Screen fails to display.

Power lamp		NO
check	YES
Inverter board		NG
LCD back		NO
light lighting
YES		NG
LCD unit
check

Check contact condition of power input terminal. Replace if defective.

Check Power SW. Replace if defective.

Replace inverter board.

Check inverter cable continuity. Replace if defective

Replace LCD back light.

Replace LCD unit.

Failure in starting

Not displayed properly on screen.

BIOS operation			NO
				Replace main board (Check fuse at power source).
check	YES
		NG
Result of				Refer to POST
					Replace main board.
POST	OK			error code table.
		NG
Set-up utility						Heavy trouble e.g.,
				Replace main board.
starting						‘Set cannot be turned
OK						ON’, ‘Set fails to start’,
						‘No display on
Return set-up utility setpoint to the state of ‘delivery from factory’.						screen’, etc.
		NO		Check HDD cable connection and continuity.
HDD access				Replace if defective.
				Replace HDD & Reinstall.
YES
				Replace main board.
Main board		NG
				Replace main board
check

Some or all keys cannot be input.

OK

Make sure of contact of K/B connector in use. Replace keyboard or main board.

Each kind of trouble in operation.

DVD/CD CALL not practicable.

*Clean DVD-ROM drive with an applicator.

Starts but operates unstably.

TroubleNO symptoms on some

of DVD or CD

YES

Replace DVD drive.

Replace main board.

Reinstall HDD.

Replace main board.

STARTEND

Check if there are any flaws on DVD or CD media. Since flaws may appear on specific media, DVD or CD media can be defective.

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