RCA F25424
RCA F25424 RGB mod (work in progress)
This RGB mod is a work in progress. Do not follow this tutorial until it is finalized.
Same mod should also apply to the below models.
- RCA F25649 (uses the same Chroma)
- RCA F25645 (uses the same Chroma and OSD)
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.
Plan of attack
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.
Specs
RCA 25424TX51
- Chassis: CTC203AC9
- Chroma: LA7612N
Service manuals
Schematics
Prepare the mux diagram. If you are building your own circuit, this diagram should help
Performing the 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.
STEP 1: Remove the following components
Remove the following RGB resistors that are connected to the ground.
- R13313 (1kΩ)
- R13312 (1kΩ)
- R13311 (1kΩ)
STEP 2: Add inline diodes to reduce interference
Let's skip this step for now
STEP 3: Connect RGB and Blanking
Attach RGB wires and blanking on exactly where these resistors were removed.
STEP 4: Connect Audio, Sync and Ground
Composite Sync, Audio and Ground wires should be connected.
STEP 5: Build your mux board/circuit
Below mod uses the RGB mux board. This is optional, but will make your mod easier and stable. You can also create the circuit presented in the schematics above without the board.
TV Model | F25424 |
---|---|
RGB termination (R1, R2, R3) | 75Ω |
RGB inline resistors (R4, R5, R6) | 470Ω |
Audio LR (R7, R8) | 1kΩ |
Diode (R9) | 1N4148 |
Blanking Resistor (R11) | shorted |
RGB inline diodes needed? x3 | yes |
Blanking inline diode needed? x1 | yes |