Friday, November 16, 2012

HITACHI - PLASMA TV _ NO PICTURE _ TROUBLESHOOTING _ MODELS _P42H401, P42H4011, P50H401, P50H4011, P55H4011, P55H401, P42T501, P50S601, P50V701, P50X901, P50T501, P55H401, P55T501 and P60X901 - [1]

                                                                        [1]

NO PICTURE

Probable Causes


  1. The Power Supply may not be producing the correct voltages.
  2. The Digital Module (Digi-Main) may not be producing correct turn on commands (Power 1 and 2).
  3. The Logic PWB may not be supplying the correct Vs/Va turn on commands (Vsago and Vcego).
The Panel can have a defect of:
  • The panel is shorted.
  • The panel is defective, but not presenting a short.
  • Y-SUS and/or X-SUS may be defective (Shorted and or nonworking).
Monitor the front Power LED first:
  • Does it turn on, then go completely off? (Indicates Shutdown), Power Supply not running. (Shutdown usually indicates a Short.)
  • Does it turn on and stay Green, but no picture. (No Shutdown),
  • Power Supply running basic power supplies, but Vs/Va voltages not being produced.
Next open the unit by removing the back cover. Check the following carefully by visual observation.

BUFFERS (Drivers) ON SDR Upper and/or Lower PWBs (50”~60”)

     Take a moment to carefully observe the Buffer “Snot” Chips (Left Side black chips mounted on the SDR Upper and Lower PWBs).  Look very closely for burns and/or small holes in these chips.  If any defect is seen, the PWB is defective. Replace this PWB and the Y-SUS if PWB not upgraded. Replace only SDR if PWB is upgraded.


  • COF (Chip on Film) from Panel to A-BUS (42”)



  • Look very closely for burns and/or small holes in these chips.
  • Look very closely for any ribbon cable damage on the connections to the Panel itself from the A-BUS PWBs.
  • If any defect is seen, the Panel is defective.
  • Some additional disassembly is required to see these COFs as they are on the underside of the ribbon cable coming from the panel to the A-BUS L, R and C PWBs.




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