Toshiba 20AF43+

# Toshiba 20AF43+ CRT RGB mod

This tutorial covers the RGB mod for the below models.

• Toshiba 20AF43
• Toshiba 20AF44
• Toshiba 20AF45
• Toshiba 20AF46

Please also see other Toshiba AF series mods, as the instructions are more or less the same.

• Toshiba 14AF43
• Toshiba 24AF43
• Toshiba 27AF43

# CRT safety

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

# Specs

# 20AF45

• Chassis: M3S027
• Manufactured: Thailand, August 2005
• Power Consumption: 105W, 120V, 60Hz (NTSC)
• Tube: Orion A51LYZ095X8

# Service manuals

• 20AF43 Service Manual
• 20AF44 Service Manual
• 20AF45 Service Manual
• 20AF46 Service Manual

# Schematics

Get hold of the schematics for your TV. Understand where the RGB and Fast Blanking signals go from OSD to the Jungle (Chroma) chip.

# 20AF43/20AF44

# 20AF45/20AF46

The biggest difference between 20AF44 vs 20AF45 is there is no VM circuitry (the one that is used for edge enhancements). Therefore, D107, D108 and D110 are missing from this schematics.

# PCB

# 20AF43/20AF44/20AF45/20AF46

Points where the R, G, B and Blank wires should be connected are marked "X". Pink boxes show the resistors, diodes that needs to be removed.

Actual PCB might be slightly different for 20AF45 and 20AF46. However, the mod that needs to be applied is in similar location.

# Performing the mod

# STEP 1: Remove the following components

# 20AF43/20AF44

Remove the RGB resistors to ground

• R141
• R142
• R143

There were no coupling capacitors to ground that needed to be removed

VM can be disabled in two ways

Method 1: Unplug the VM cable on the neck board.

Method 2: Remove diodes that enable VM from the RGB lines (not recommended)

• D107
• D108
• D110

# 20AF45/20AF46

Remove the RGB resistors to ground

• R141
• R142
• R143

There are no VM cables to unplug on the neck board. No VM diodes to remove on this board.

# STEP 2: Connect RGBs, Blanking and Audio

# 20AF43/20AF44/20AF45/20AF46

Connect the RED, GREEN, BLUE, BLANKING wires

Connect the SIGNAL, AUDIO RIGHT, AUDIO LEFT, GROUND wires

# STEP 3: Build your mux 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. Please also checkout the precalculated resistor values.

Buy your RGB mux board

Depending on the RGB/OSD stock resistors your CRT has, use the below inline resistors.

Toshiba 20AF45 RGB mux adapter

Toshiba 20AF44 RGB mux adapter

# STEP 4: Attach the female SCART connector to TV

Creating a SCART cutout and mounting it is an art. I have a dedicated section for it.

How to create and mount a SCART female plug?

# Alternate method to reduce ringing noise

If you don't have diodes on the OSD RGB lines connecting to the chroma chip, the RGB signals that comes from the console can hit the OSD chip and reflect back, causing a minor interference. While not very noticeable, if you are keen on keeping all forms of noise away from your mod, you should follow the below directions.

# Step #1: Remove the ground resistors.

• R141
• R142
• R143

Also remove the 0.1uF SMD caps that are inline

• C136
• C137
• C138

# Step #2: Introduce diodes and 0.1uF caps

Mux Diagram

Connect RGB, Blanking wires

Remove the jumper wires that feeds the R, G, B lines from OSD to Chroma. Forgot to take a picture of this, but this is an important step to perform.

Removed caps are bridged. Caps and didoes added. Pay attention to the direction.

Blanking wires and RGB wires attached.

Connect Audio, Sync and Ground wires

# Step #3 and #4

These are the same as above. Only difference here is the RGB inline resistance value to use will be 1.2kΩ instead of 1kΩ. This is to compensate for the addition of the diodes.

# Pictures (20AF44)

# Finished mod

Yes, screws are missing. They were put in later!

# Test patterns

Not the best image quality. But, looks pretty decent for a flat CRT TV.

# Games

# Pictures (20AF45)

# Mux board and port

SCART port

Cable connected

# OSD Mux overlay

# Games

SNES - Super Mario World

SNES - Metroid

NES - Adventure Island

XBOX - UnleashX

Sega Genesis - Sonic

# Patterns

Convergence

Monoscope

# Tube and Board

Tube

Back label

Back open