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Sony KV (G3F) L34MF1

About 1 minCRT RGB modKV-L34MF1KV-L34MH11, KV-L34MN11

Sony G3F chassis CRT RGB mod

Coming soon!

CRT safety

Caution

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 high enough voltage (20,000+ V) and current to be deadly, even when it is turned off.

READ THIS BEFORE CONTINUING

Plan of attack

READ THIS TO PREPARE

Theory

Sometimes it is nice to know the theory behind the mod. I have put this on a separate page. This shows how the various resistor values are calculated.

READ THE RGB MODDING THEORY

Service manuals

Specs

  • Chroma: CXA1587S

Performing the RGB mod

Now that you roughly know what needs to be done, prepare for the mod. Place the board on a comfortable place. Make sure you are not putting pressure on the flyback or other components. Taking out the chassis is fairly straight forward on this CRT. There are few wires that needs to be disconnected.

  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 wires disconnected while powering up can damage the board and can have adverse effects.

It should also be noted, on this CRT, you can do the RGB mod by just taking out the A board. This means you don't even need to remove the anode wire.

Methods to try

Method 1 (direct injection)

  • Try injecting R, G, B signals directly to pins 47, 46, 45 directly
  • Supply 5V via a diode (R9) and 1Kohm (R11) resistor to blank
  • Use 75 ohm termination (R1, R2, R3)
  • 0.1uF caps inline (R4, R5, R6)

Method 2 (mux method) - only try if method 1 doesn't work

  • Remove the ground resistors R343, R344, R345 (1k)
  • Inject RGB in-between 0.1uF and 3.9kohm resistors on RGB lines attached to pins 38, 37, 36 in chroma
  • Use 75 ohm termination (R1, R2, R3)
  • Use 750 ohm RGB inline (R4, R5, R6)
  • Use a diode on R9 to feed 5V
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