Sharp LJ640U34 EL Display

Repair Replace Retrofit Refurbish

LJ640U34

Your options for the obsolete Sharp LJ640U34 display.

  • Buy a used display that has not been refurbished and simply pulled from an obsolete machine and resold. Not recommended but an option.
  • Buy a used display that has been "refurbished". For your own curiosity find out what was refurbished. You have the right to know. Make sure all time and heat sensitive components have been replaced working or not.
  • Repair your display at reputable company  and they should perform a FULL refurbishment/rebuild of ALL time and heat sensitive components. Google "LJ640u34 repair".
  • Buy a possible NEW or used retrofit. Google "LJ640U34 retrofit" for companies that offer this option.

Problems of your aging Sharp LJ640U34

  • Your display does not power up. Possible causes: Damaged row drivers. Damaged electrodes in glass substrate-not repairable. Electrodes X and Y are shorting. If you look carefully at the front of your display, you actually might be able to see small black dots on your display. This kind of damage is due to age. You CANNOT get away from age when it comes to these Sharp LJ640U34 displays. So remember this when you decide to purchase a USED Lj640U34's to replace your old one.
  • Your display is fading or takes a few minutes to power up. Repairable. This is one of the first signs of age. You have some components that need to be replaced SOON! Of course many customers will run the display until failure and this  costs you more to repair only because it takes more labor time.
  • Random missing pixels over some portion of the display. Well I hate to tell you that the display is scrap. You have damaged phosphor.  You guessed it ...this is due to age and the lack of a screen saver.
  • Bright line(s) running across the display from left to right. This is repairable but it has to be done as soon as possible before is creates a domino effect and destroys more surface mount components.
  • Flashing display. Repairable but needs to be taken care of as soon as possible.  High voltage supply is being shut down because of an over current situation.
  • Your display has a hue in the background making it hard to view actual video data. This condition is repairable.


LJ640U34 specifications

  • 640X400 res
  • 12Vdc 5 Vdc supply.
  • monochrome AMBER.
  • EL technology TTL
  • Obsolete Sharp product.