Samsung CKB5237L Service Manual page 32

6 Troubleshooting
6-2 Horizontal Line on CRT (Root Cause : Vertical Deflection Parts Fail)
Does output pulse of 50Vp-p
appear at Pin 5 of IC301?
Yes
Does rectangular signal output
18
at Pin 5 of IC300?
Yes
Does DC 13 V appear at Pin 2
of IC300?
Yes
Does DC -12 V appear at Pin 4 of
IC300?
Yes
Check swap IC300.
6-3 Vertical Line on CRT (Root Cause : Horizontal Deflection Parts Fail)
Does PWM output signal appear
6
at Pin 26 (H-out) of IC302?
Yes
Does 12Vp-p signal appear at
Emitters of Q412 and Q414?
Yes
Does 120Vp-p signal appear at
11
Pin 1 of T401?
Yes
Check CN400, D403 and Q406.
6-2
No
Check connector CN300A.
No
Check CN300A.
No
Check DC 13 V Line.
No
Check DC 12 V Line.
No
Does DC 5 V appear at Pin 32
of IC302?
Yes
No
Check Q412 and Q414.
No
Check Q403.
WAVEFORMS
18
CH1 P-P = 46.0 V
Check IC302.
6 8.80 V (IC302, #26)
CH1 P-P = 8.80 V CH1 RMS = 6.176 V
WAVEFORMS
46.0 V (IC300 #5)
CH1 RMS = 6.38 V
No
Check 5V,
12V Line.
11 124.8 V (T401, #1)
CH1 P-P = 124.8 V CH1 RMS = 66.16 V
CKB5237L/7227L