sharp with tda9381 there is no picture, normal voice

case:
  • sharp with tda9381
  • problem there is no picture and raster dark
  • osd appear
  • normal voice
  • picture cheque via av-in permanent there is no picture
  • analysis:
    • this case differs from problem “raster blank”. where raster same dark, but in case raster blank osd doesn't appear
    • here pin-rgb out measuresed all in once tension, in case raster blank pin-rgb out tension all zero
    • because voice stills there so mean part tuner and video if still ok.
    action:
    • from analysis result after study skematik, so suspicion falls in circuit abcl (automatic brightes and color limiter)
    • tension cheque in pin-abcl there is no (normal around 3v)
    • tension cheque abcl in pin-1 foot flyback – needle deviates towards negatip. normal must there tension around 4v
    • conclusion: resistor part abl to suply vcc certain in that broken off.
    • cheque r604 broken off
    • pin-1 pin-abl flyback
    • r605 get tension from b+



Note:

  • damage there is no tension abl the phenomenon in model other not yet sure same. for example in la76810 there is no tension abl causes thin contrast and can not mengadjust.

Subscribe to receive free email updates:

1 Response to "sharp with tda9381 there is no picture, normal voice"

  1. sir, in sharp old model i am experiencing picture blur problem pls help .audio is ok.

    ReplyDelete