Sony (BA-4) KV-27S45

# Sony (BA-4) KV-27S45 CRT RGB mod

The Sony KV-27S45 is a 27" curved screen CRT television. Sold in the late 1990s as part of Sony’s highly regarded Trinitron line, it remains a favorite among CRT enthusiasts for its excellent geometry, reliable tubes, and vibrant color reproduction.

This CRT can be RGB and component modified. It shares the same tube as other BA-4 27" CRTs. Example: KV-27S40.

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

This largely follows the same method as the Sony BA-4D RGB mod article. Primary difference here is the use of micro mux board. Pictures were submitted by Brett Cutler.

Instructions below should also apply to these models:

• KV-27S40
• KV-27V40
• KV-27S45
• KV-27S65

# Table of Contents

# Contributors

Thank you to everyone who contributed to this guide:

• Brett Cutler — contributor, RGB mod and pictures

# CRT safety

READ THIS BEFORE CONTINUING

# Plan of attack

READ THIS TO PREPARE

# Manuals and Datasheets

• Sony KV-27S45 Service Manualopen in new window
• Sony CXA2061S Datasheet (Jungle)open in new window
• Mitsubishi M37273MF-255SP Datasheet (OSD) — Available for Pro Users only. See CRT detailsopen in new window for access.

# Specs

• Manufactured: Mexico (1998, 1999)
• Chassis: BA-4
• Jungle Chip: Sony CXA2061S
• OSD Chip: Mitsubishi M37273MF-255SP
• Screen Size: 27"
• Power: 140 W

# Schematics

# RGB mux diagram

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. Taking out the chassis is fairly straight forward on this CRT. There are few wires that needs to be disconnected.

1. Degauss wire
2. Power wire
3. Ground wire attached to the neck board
4. Yoke deflection coil wire
5. Anode wire (this is the one with the rubber cap)
6. Left and right audio wires

Please remember that wires 1-5 are critical for the CRT to function and should not be omitted. Having any of these wires disconnected while powering up can damage the board and can have adverse effects.

# STEP 1: Remove the following components

Remove the following components. RGB resistors to the ground. Please always measure and mark them, so that you know you are removing the correct partrs.

• R086 (680Ω) Red ground resistor
• R087 (680Ω) Green ground resistor
• R088 (680Ω) Blue ground resistor

# STEP 2: Add RGB inline diodes (optional, but recommended)

To reduce interference, it is recommended to add these inline diodes. You will be lifting one side of the R025, R026, R027 and add diodes. Pay attention to the diode direction and how it was installed. This is extremely important. Otherwise, OSD will not work.

KV-27S45 - Heat shrink was used in the middle one to avoid shorts.

KV-27V40 - Heat shrink was used in the middle one to avoid shorts.

KV-27V42 - Heat shrink was used in the middle one to avoid shorts.

KV-27S42 - After adding diodes inline

# STEP 3: Solder R, G, B and blanking wires

# STEP 4: Solder audio, sync and ground wires

# STEP 5: Build your mux board

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.

Compatible mux boards:

• RGB MUX BOARD KIT 1.4Bopen in new window

Buy your RGB mux board kit

!Important. There is method to installing the micro board. Please follow this tutorial for the steps you should take to install the micro board.

# Pictures

# Games

# Set

Chassis

Yoke

Neck Board

Back label

Tube

Set turned off

# Pictures

# Reference Photos

See more photos and contributions →open in new window