ICOM IC-746/756/PRO Series CCFL-to-LED Backlight Conversion

Note: I’m not marketing any sort of kit or “upgrade.”
My priority is doing repairs.
I offer this option for repairing faulty backlights.
My service is for customers/end-users only, not other shops.
The entire radio must be sent in for service, not just the front-panel.

April 2018: I’m now able to convert backlight circuits from CCFL to LED in the following radios:

IC-746
IC-746PRO
IC-756
IC-756PRO
IC-756PROII
IC-756PROIII

If the original circuit is in bad shape, or the CCFL tube is very dim, I can replace the CCFL tube with a 12-volt LED strip. (Scroll down to see pictures.)

  • I add a simple circuit (shown below) that allows the rig’s dimmer function to work as intended.
  • No inverter or regulator circuits are used. So there are no RFI issues, and there are less components to fail.
  • A regulator circuit is not required. The original CCFL driver circuit was not regulated, nor does the LED circuit need be. (If you experience flickering while transmitting, you likely have marginal supply voltage, or voltage loss through your DC power cable.)
  • The circuit is so small, it can be built inside the original CCFL circuit’s shielded enclosure. But I find it best to mount the components on the back-side of the circuit board, where they can be easily accessed, without having to remove the board.
  • The LED strip is a cool-white type, so the display looks as close to original as possible.
  • I use the Flexfire UltraBright Slim Series LED strip, which is only 3.5mm wide, and fits perfectly in the IC-756PRO series displays.
  • In the IC-746/PRO displays, there’s a wider opening, so I add a spacer.
  • The IC-746/PRO series requires 3 sections of this LED strip. And the IC-756PRO series requires 7 sections.

(Update: I now use BD437TG instead of 2N6121.)

IC-756PROII with LED conversion at 100% brightness:

IC-746 with LED conversion at 100% brightness:

Comparison of an original Pro2 CCFL tube (bottom) and a new LED strip (top): 

An LED strip all lit up: