3.4.5 Video Circuit Failure
(Check “3.2.2 Image Color Failure or Contrast Failure”
before this item)
Measure the voltage between GND and Pin 6 of IC210 on the
VIDEO PWB.
OK
Check the 80V line.
Expected failure point
1) CN211, IC210 or peripheral circuits
2) Power circuit (See Item 3.4.1)
Measure the potential at Pin 1,3 and 6 on the VIDEO
PWB. (Approx. 0.7Vp-p)
NG
OK
Expected failure point
1)
R210R/G/B on the VIDEO PWB
2)
L200R/G/B, L201R/G/B or R200R/G/B on the CRT PWB
3) CRT
socket
OK
NG
Measure the voltage between GND and Pin 2 of CN211.
Expected failure point
IC211, IC212 or 12V-regulator circuit of the power circuit
NG
OK
Expected failure point
IC210 on the VIDEO PWB
OK
NG
Expected failure point
IC216 on the VIDEO PWB
NG
OK
Check the blanking signal.
Expected failure point
IC601 on the DEFL_SUB PWB or CN212
NG
OK
Measure the waveform at Pin 14 of IC211 on the
VIDEO PWB. Confirm that the blanking waveform is
maintained at approx. 5Vp-p.
Check the clamp waveform.
Expected failure point
IC102 on the MAIN PWB, or CN212
NG
OK
Measure the potential at Pin 13 of IC211 on the
VIDEO PWB, and confirm that clamp waveform is
maintained at approx. 5Vp-p.
To CONTINUE
2
on the Next page
To CONTINUE
1
on the Next page
Check the input waveform of the pre-AMP.
Measure the waveforms at Pins 8, 9 and 11 of
IC210 on the VIDEO PWB. (Approx. 2.5Vp-p)
Check the input waveform of the output IC.
Check the 12V line
Measure the waveform at Pins 1, 3 and 5 of IC210 on the
VIDEO PWB. (Approx. 35Vp-p)
Check the output waveform of output IC.
NG
Measure the waveforms at R200R, R200G, and
R200B on the CRT PWB in the full white pattern.
Check the R, G, B video outputs.
3-22
Summary of Contents for DPro2070SB
Page 22: ...1 15 Fig 7 The principle of DDCC compensation ...
Page 23: ...1 16 Fig 8 a DDCC adjustment item ...
Page 24: ...1 17 Fig 8 b DDCC adjustment item ...
Page 25: ...1 18 Fig 9 DDCC circuit diagram ...
Page 103: ...4 Wave form 1 POWER 2 CONTROL MAIN 3 DEFL MAIN 4 DEFL SUB COIL DRIVE MAIN 5 VIDEO ...
