Samsung AQ17, AQ17KS Troubleshooting
AQ17KS 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 FH1
Done.
No
Yes
Repeating start?
Check and replace D606.
No
Yes
IC601 Pin 1 waveform is right?
Check and replace D614, IC601,
Q602, and ZD601.
Yes
No
C622 Voltage is 13 V ± 0.5V?
Check and replace IC201, IC301,
IC401, Q402, and Q404.
Yes
Yes
No
Operate normally?
Replace Main board.
Verify voltages.
No
WAVEFORMS
1
1
100 V (IC601, #1)
CH1 P-P = 100 V CH1 RMS = 350.2 V
5 Troubleshooting
5-2 AQ17KS
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 6.
Yes
No
Yes
IC602 Pin 4
voltage exists?
Check IC201 Pin 6.
Check and replace IC602.
No
IC601 Pin 1 output
voltage exists?
Refer to 5-1-1 No Power Supply.
Done
Yes
No
2
2
100V (IC601, #1)
CH1 P-P = 100V CH1 RMS = 325.8 V
WAVEFORMS
5 Troubleshooting
AQ17KS 5-3
5-1-3 H_Deflection Failure
Does Horizontal pluse signal
appear at Pin 8 of IC401?
Check IC401.
Yes
No
Does 110 Vp-p signal appear
at Collector of Q403?
Check Q403.
Yes
No
Check Q402, Q404 and T401.
4
Does PWM output signal appear
at Pin 6 (B_out) of IC401?
Check IC401.
Check 12 V line.
Yes
No
Does DC 12V appear at
Pin 10 of IC401?
Yes
No
3
5-1-4 S Correction Failure
S1~S4 signals are right at each
frequency block?
Check S1 ~ S4 signal.
Check and replace Q404, Q409,
Q410, Q411, Q414, Q415, Q416,
Q420, and Q421.
Yes
Check and replace IC201.
No
5
3
2.00 V (IC401, #6)
CH1 P-P = 2.00V CH1 RMS = 5.868V
4
2.00V (IC401, #8)
CH1 P-P = 2.00V CH1 RMS = 5.868V
5
20.0 V (Q403, Collector)
CH1 P-P = 20.0 V CH1 RMS = 46.80V
WAVEFORMS
5 Troubleshooting
5-4 AQ17KS
5-1-5 H_Lin. Failure
IC201 Pin 21 voltage varies with
different H_Lin. DAC values?
IC603 Pin 9 voltage varies with
different H_Lin. DAC values?
Check +13V, –10V line.
Check some parts around IC603.
Check Q412, Q413 and T402.
Yes
Yes
No
Replace IC201.
No
5-1-6 Invariable H_Size
IC401 Pin 6 voltage varies with
different B_Out DAC values?
Q402 Gate output duty varies with
different B_Out DAC values?
Check some parts around Q402,
IC401 Pin 3 ~ 6.
Yes
No
Check and replace IC401.
No
5-1-7 Abnormal H_Size
IC401 Pin 11 output duty
varies with different B+ offset
DAC values?
Q404 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
6
200 V (Q404, Collector)
CH1 P-P = 200V CH1 RMS = 387.2V
WAVEFORMS
5 Troubleshooting
AQ17KS 5-5
5-1-8 Side Pin or Trap Failure
IC401 Pin 11 output exists?
Yes
Check and replace IC401.
Refer to 5-1-7
Abnormal H_Size
.
5-1-9 Para. or Pin Balance Failure
IC401 Pin 11 output varies with
different DAC values?
No
Replace IC401.
No
7
5-1-10 Tilt Failure
IC201 Pin 20 output duty varies
with different DAC values?
IC603 Pin 13 output varies with
different DAC values?
Check and replace IC603.
Check and replace Q301 and Q302.
Yes
Yes
No
Check and replace IC201.
No
Check tilt connector connection
Refer to 5-1-7
Abnormal H_Size
.
Yes
7
1.00 V (IC401, #11)
CH1 P-P = 1.00V CH1 RMS = 3.008 V
WAVEFORMS
5 Troubleshooting
5-6 AQ17KS
5-1-11 V Deflection Failure
13V and –10V lines are on?
IC401 Pin 12 output exists?
Check and replace IC401.
Yes
Yes
No
Refer to 5-1-1 No Power Supply
No
IC301 Pin 6 output exists?
Check and replace some parts
around IC301.
Yes
No
Check DY connector connection.
8
9
5-1-12 V Size or Position Variation Failure
IC401 Pin 12 output varies with
different DAC values?
Yes
Check and replace IC201 and IC401.
Check and replace IC301.
No
8
500 V (IC401, #12)
CH1 P-P = 500 V CH1 RMS = 1.425 V
9
10.0 V (IC301, #6)
CH1 P-P = 10.0 V CH1 RMS = 5.06 V
WAVEFORMS
Loading...