Samsung AN15V Troubleshooting

CONFIDENTIAL

AN15V* 5-1

5 Troubleshooting

5-1 Parts Level Troubleshooting

Notes: Check the following circuits.

• No raster appears: Power circuit, Horizontal output circuit.

• High voltage develops but no raster appears: Video output circuits.

• High voltage does not develop: Horizontal output circuits.

5-1-1 No Power Supply

Chirping noise exists?

Check and replace IC601.

Check and replace D601 and FH_1.

Done.

No

Yes

Repeating start?

Check and replace D606.

No

Yes

IC601 Pin 1 waveform is right?

Check and replace Q602, IC605,

OP202 and IC602.

Yes

No

C622 Voltage is 13 V ± 0.5V?

Check and replace IC201, IC301,

IC401, IC605, Q402,

Q404, Q613,and Q614.

Yes

No

Operate normally?

Replace Main board.

Yes

Verify voltages.

No

1

WAVEFORMS

1

100 V (IC601, #1)

CH1 P-P = 100 V CH1 RMS = 350.2 V

CONFIDENTIAL

5 Troubleshooting

5-2 AN15V*

5-1-2 DPMS Failure

Make No H/V Sync.

(power off mode)

Check signal source

H/V Sync. video level.

LED blinks?

Check IC201 Pin 40.

Yes

No

+12 V line off?

Check IC201 Pin 5, Pin 6 and Q610,

Q602 operation condition.

Yes

No

Q602 Base

voltage exists?

Refer to 5-1-1 No Power Supply.

Done

Yes

No

IC601 Pin 1 Output

voltage exists?

Check IC201 Pin 5.

Check and replace Q602 and IC201.

No

2

WAVEFORMS

2

100 V (IC601, #1)

CH1 P-P = 100 V CH1 RMS = 325.8 V

CONFIDENTIAL

5 Troubleshooting

AN15V* 5-3

5-1-3 H_Deflection Failure

Does Horizontal pluse signal

appear at at Pin 26 of IC605?

Check IC605.

Yes

No

Does 20 Vp-p signal appear

at Collector of Q400?

Check Q400.

Yes

No

Check D406, Q404 and T401.

4

Does PWM output signal appear

at Pin 28 (B_drv) of IC605?

Check IC605.

Check 12 V line.

Yes

No

Does DC 12V appear at

Pin 29 of IC605?

Yes

No

3

5-1-4 S Correction Failure

S1~S2 signals are right at each

frequency block?

Check S1 ~ S2 signal.

Check and replace

Q404, Q410, Q411, Q415, and Q416.

Yes

Check and replace IC201.

No

5

WAVEFORMS

3

5.00 V (IC605, #28)

4

1.00 V (IC605, #26)

5

5.00 V (Q400, Collector)

CONFIDENTIAL

5 Troubleshooting

5-4 AN15V*

5-1-5 H_Lin. Failure

Check and replace T402

5-1-6 Invariable H_Size

IC605 Pin 28 voltage varies with

different B_Drv DAC values?

Q402 Gate output duty varies with

different B_Drv DAC values?

Check some parts around Q402,

IC605 Pin 4 ~ 6.

Yes

No

Check and replace IC605.

No

5-1-7 Abnormal H_Size

IC605 Pin 24 output duty

varies with different B+ offset

DAC values?

Q408 Collector waveform is

right?

Check and replace Q405,

Q406, Q407, and Q408.

Check some parts

around D409 and L401.

Yes

Yes

No

Check and replace IC201.

No

6

WAVEFORMS

6

5.00 V (Q408, Collector)

CONFIDENTIAL

5 Troubleshooting

AN15V* 5-5

5-1-8 Side Pin or Trap Failure

IC605 Pin 24 output exists?

Yes

Check and replace IC605.

Refer to 5-1-7

Abnormal H_Size

.

5-1-9 Para. or Pin Balance Failure

IC605 Pin 24 output varies with

different DAC values?

No

Replace IC605.

No

7

Refer to 5-1-7

Abnormal H_Size

.

Yes

WAVEFORMS

7

1.00 V (IC605, #24)

CONFIDENTIAL

5 Troubleshooting

5-6 AN15V*

5-1-10 V Deflection Failure

13V and –10V lines are on?

IC605 Pin 23 output exists?

Check and replace IC605.

Yes

Yes

No

Refer to 5-1-1 No Power Supply

No

IC300 Pin 6 output exists?

Check and replace some parts

around IC300.

Yes

No

Check DY connector connection.

8

9

5-1-11 V Size or Position Variation Failure

IC605 Pin 23 output varies with

different DAC values?

Yes

Check and replace IC201 and IC605.

Check and replace IC300.

No

WAVEFORMS

8

1.00 V (IC605, #23)

9

10.0 V (IC300, #6)