Toshiba 20AF43+

# Toshiba 20AF43+ CRT RGB mod

The Toshiba 20AF43 is a 20" flat-screen CRT television released in 2003. This model features video inputs including Composite, Component, and S-Video, delivering a sharp, vibrant picture that is ideal for classic 240p consoles. Unlike the larger 27" AF series, the 20" and smaller screens do not experience the horizontal distortion often noticed in side-scrolling games.

Toshiba 20AF4x CRTs are RGB moddable.

View full CRT details and more mod examples →open in new window

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 20AF43
• Toshiba 27AF43

# Table of Contents

# Contributors

Thank you to everyone who contributed to this guide:

• Suntharopen in new window — contributor, RGB mod and pictures

# CRT safety

READ THIS BEFORE CONTINUING

# Plan of attack

READ THIS TO PREPARE

# Manuals and Datasheets

• TOSHIBA 20AF43 SMopen in new window
• TOSHIBA 20AF44 SMopen in new window
• TOSHIBA 20AF45 SMopen in new window
• TOSHIBA 20AF46 SMopen in new window
• M61283FP Datasheet (Jungle)open in new window

# Specs

• Year: 2004
• Format: NTSC
• Chassis: M3M727
• Tube: Orion A51LVV896X07
• Jungle Chip: M61283FP
• OSD Chip: OEC7090A
• Screen Size: 20"
• Weight: 50.6 lbs
• Inputs: Composite, S-Video, RF, Component YPbPr

# 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.

If you are building your own circuit, this diagram should help. Check the alternate method for ringing noise reducing circuitry.

# 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.

# RGB mux diagram

Prepare the mux diagram. If you are building your own circuit, this diagram should help.

# 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

This 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 mux calculatoropen in new window to play with your own values.

Buy your RGB mux board kit

Based on the chassis RGB inline resistor value, you may want to choose different RGB inline resistors on your mux board. However, I have noticed in general 1kΩ resistors just works well.

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 and short them

• C136
• C137
• C138

Remove jumpers

• W107
• W108
• W112

# STEP 2: Introduce diodes and 0.1uF caps

Mux Diagram

Connect RGB, Blanking wires

Remove the jumper wires W107, W108 and W112 that feeds the R, G, B lines from OSD to Chroma. 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. In general, I've noticed using 1kΩ for R4, R5, R6 works just as well without any degradation in picture quality.

# 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

# Pictures

# Reference Photos

See more photos and contributions →open in new window