Lcd & Leds; The Back Lite Display For The 2950; Display Contrast Mod - Ranger RCI-2950 Service Manual

LCD & LEDS

THE BACK LITE DISPLAY FOR THE 2950

In this mod. You will remove the filament bulbs and replace them with a low voltage light emitting diode .
Advantages of this mod. Are full controlthrough all four setting of your dim control.
This makes the voltage reg. Run cooler for that part of the radio. You can customize the colour of the back light instead of
buy those other Slip covers for the filament bulbs .
This mod will also make the light emitting diodes that are under the touch Controls brighter ,as they run of the same supply.
The mod
Remove the front part of the radio and the board that has the display too so you can get right at those bulbs.
If you look at the board you will notice a + and - .
This is were the supply is coming from for the old bulbs . Remove the old bulbs . Now get some small wire and make it so you
have a + and - at each side of that board .either that you will have to cut traces. What you are trying to do is make the bulbs
independent of each other. Anyways back to the mod , so now you have a + and - wire for each new kind of bulb.
Now you will have to select a light emitting diode that runs on less power than the supply on that board puts out. Once you
have done this you will have to select a resistor i picked a 10 k at one quarter of a watt .that seemed to match the diodes i
used. This will differ each kind of light emitting diode selected .
Dont try to install the lite diodes in the same place as the filament bulbs this will defeat the purpose. When you install the
diodes you only need one resistor for each side light emitting diodes are polarized they have a negative and positive hook
them up backwards and they do not light up So when you are all done you should have full control on the dim.
If one lite diode blows the other stays going ,this willnot happen because of the resistor that is in line on each lite . The power
reg for this supply should run cool no heat better performance i did my personal set one year ago in green lite and it still
looks and runs fine .
Pretty simple mod i know it is alot cheaper than buyiny those little filament Bulbs .i for gotten to tell you light emitting diodes
last longer than the Other.
From
Rick vanluven
Kingston ontario canada

DISPLAY CONTRAST MOD

First :
I had a problem with my RCI2950, once in a while the contrast dropped to almost zero. I tried to find the problem and after a
while I had the idea that the contrast reference control on the display driver chip was sensitive and instable.
Due to this I came to the decision to put a little more load on the reference input of the display driver.