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CRT safety

SuntharAbout 2 minCRT RGB mod



You can die doing this! So read carefully! CRT TV is not a toy. Do not open a CRT TV. If you don't have any prior knowledge about handling high voltage devices, this guide is not for you. CRT TV contains sufficient high voltage and current to be deadly, even when it is turned off.

This is provided for information purposes only. If you haven't worked on a CRT or don't know how high voltage equipment works, stay away from this. Follow this tutorial at your own risk.

Preparing the TV for RGB mod

  • First make sure all video inputs work without issues
  • Remove the TV from the power plug
  • Let the TV sit for a day, so that it can discharge itself
  • Remove the screws on the back of the TV
  • WARNING: Discharge the tube
  • WARNING: Don't short to discharge the capacitors. Accidentally shorting the wrong location can damage the sensitive components. Use a discharging tool.
  • WARNING: 5 minutes later discharge the tube again
  • Remove the mainboard. Try not to touch any of the capacitors
  • Discharge the bigger capacitors one by one

Critical wires

In most CRTs there are few wires that needs to be disconnected/reconnected.

  1. Degauss wire
  2. Power wire
  3. Ground wire attached to the neck board
  4. Yoke deflection coil wire
  5. Anode wire (this is the one with the rubber cap)
  6. Left and right audio wires


Please remember that wires 1-5 are critical for the CRT to function and should not be omitted. Having any of these disconnected while powering up can damage the board or can pose high risk.

Discharging the tube and capacitors

:::danger HIGH VOLTAGE High voltage is present in the tube (when it's on or off), and also in the capacitors throughout the CRT board. They take a long time to discharge. The below video shows two places that must be discharged prior to CRT operation. Discharging the capacitors on the board through a shorting method can damage the board, components and you. While discharging the tube using a screwdriver that is attached to the tube string ground (not the CRT board ground) is fine, you have to find a proper method to discharge the capacitors on the board.


Tools needed

  • CRT tube discharger (highly recommended to use tools made for the discharging purpose than use a DIY discharging tool)
  • High voltage rated rubber gloves
  • Phillips screw driver
  • High quality soldering iron
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