Samsung AN15V Troubleshooting
CONFIDENTIAL
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
Check and replace D601 and FH_1.
Yes
Chirping noise exists?
No
Yes
No
1
No
No
Operate normally?
Yes
Verify voltages.
Check and replace IC601.
Check and replace D606.
Check and replace Q602, IC605, OP202 and IC602.
Check and replace IC201, IC301, IC401, IC605, Q402,
Q404, Q613,and Q614.
Replace Main board.
WAVEFORMS
1 100 V (IC601, #1)
CH1 P-P = 100 V CH1 RMS = 350.2 V
Done.
AN15V* |
5-1 |
5 Troubleshooting
5-1-2 DPMS Failure
Check signal source
H/V Sync. video level.
Make No H/V Sync.
(power off mode)
Q602 Base voltage exists?
Yes
Done
IC601 Pin 1 Output
2
voltage exists?
CONFIDENTIAL
WAVEFORMS
2 100 V (IC601, #1)
No |
CH1 P-P = 100 V CH1 RMS = 325.8 V |
Check IC201 Pin 40. |
No |
Check IC201 Pin 5, Pin 6 and Q610, |
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Q602 operation condition. |
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No
Refer to 5-1-1 No Power Supply.
No |
Check IC201 Pin 5. |
Check and replace Q602 and IC201.
5-2 |
AN15V* |
5 Troubleshooting
5-1-3 H_Deflection Failure
3 Does PWM output signal appear at Pin 28 (B_drv) of IC605?
Yes
Does Horizontal pluse signal
4
Does 20 Vp-p signal appear
5
at Collector of Q400?
Yes
Check D406, Q404 and T401.
No |
Does DC 12V appear at |
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Pin 29 of IC605? |
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Yes |
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Check IC605. |
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No
Check IC605.
No
Check Q400.
5-1-4 S Correction Failure
Check S1 ~ S2 signal.
S1~S2 signals are right at each |
No |
Check and replace IC201. |
frequency block? |
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Yes
Check and replace
Q404, Q410, Q411, Q415, and Q416.
CONFIDENTIAL
No
Check 12 V line.
WAVEFORMS
3 5.00 V (IC605, #28)
4 1.00 V (IC605, #26)
5 5.00 V (Q400, Collector)
AN15V* |
5-3 |
5 Troubleshooting
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?
Yes
Q402 Gate output duty varies with different B_Drv DAC values?
5-1-7 Abnormal H_Size
IC605 Pin 24 output duty varies with different B+ offset DAC values?
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Yes |
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Q408 Collector waveform is |
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right? |
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Yes |
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Check some parts |
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around D409 and L401. |
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No
Check and replace IC605.
No |
Check some parts around Q402, |
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IC605 Pin 4 ~ 6. |
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No
Check and replace IC201.
No |
Check and replace Q405, |
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Q406, Q407, and Q408. |
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CONFIDENTIAL
WAVEFORMS
6 5.00 V (Q408, Collector)
5-4 |
AN15V* |
5 Troubleshooting
CONFIDENTIAL
5-1-8 Side Pin or Trap Failure |
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No |
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IC605 Pin 24 output exists? |
Check and replace IC605. |
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WAVEFORMS |
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1.00 V (IC605, #24) |
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Yes |
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Refer to 5-1-7 Abnormal H_Size.
5-1-9 Para. or Pin Balance Failure
IC605 Pin 24 output varies with |
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Yes |
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different DAC values? |
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No |
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Refer to 5-1-7 Abnormal H_Size.
Replace IC605.
AN15V* |
5-5 |
5 Troubleshooting
5-1-10 V Deflection Failure
No
No
8
No
9 IC300 Pin 6 output exists?
Yes
Check DY connector connection.
Refer to 5-1-1 No Power Supply
Check and replace IC605.
CONFIDENTIAL
WAVEFORMS
8 1.00 V (IC605, #23)
Check and replace some parts |
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around IC300. |
9 10.0 V (IC300, #6) |
5-1-11 V Size or Position Variation Failure
IC605 Pin 23 output varies with |
No |
different DAC values? |
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Check and replace IC201 and IC605.
Yes
Check and replace IC300.
5-6 |
AN15V* |
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