MOORETRONIX BMX-III, AMX, ABX, Newsmixer & Stereomixer 12-46 LED Series Bi-Pin Lamp Replacement

October 23, 2014

MOORETRONIX BMX-III, AMX, ABX, NewsMixer & StereoMixer 12-46 LED series bi-pin lamp replacement kits

We have come up with a LED replacement that’s bright, easy to install and will last years and years. The LED kit is available in Yellow for CUE and White for SOLO replacement in the EAO series 19 switch assembly. The White LED kit will also work in the Green lens applications. The part numbers are 12-46Y Yellow, 12-46W White, 12-46R Red High Brightness LEDs.

Each kit comes with a small resistor/diode network and the correct color high brightness LED.

Do not install the LED until the small current limiting and polarity protection network has been installed or the LED will be destroyed. Good for us, if you want to buy extra LED’s but bad for you if you are trying to get this kit installed and working correctly.

Allow about 15 minutes for installation.

Briefly, the lamp driver transistor is removed from the PC board, its collector lead raised and the emitter and base leads re-installed and soldered. The small network is soldered into the vacated collector lead hole. Then the RED network lead, (short lead), is soldered to the raised collector lead. The last step is to install the Yellow or White LED in place of the bi-pin lamp. If the LED won’t light then reverse its leads in the switch assembly. For BMX-III Mic & Line input modules, Q205 & Q206 for Mic's and Q225 & Q228 for Line's are removed.

To gain access to the cue and solo driver transistors for BMX-III Line Input modules, the module extrusion must be separated from the PC board. This is done, by removing the (4) 4-40 flat head screws along the edge of the extrusion. Gently pull out and then up the faceplate/extrusion assembly away from the PC board. See the photo for the location of the driver transistors and observe the way the networks are installed.

We are installing a current limiting resistor and polarity protection diode in series with the transistor driver collector and the + lamp lead going to the Cue or Solo switch assembly. Once this network is installed, the bi-pin lamps will no longer function. We are operating the LED current at 20 mA with this modification.

We have included a photo showing the installation of both the CUE and SOLO led kits.

Bob Moore

MOORETRONIX

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