Sony KV (BA-2)

# Sony BA-2 chassis CRT RGB mod

RGB mod was performed on a 20" Sony KV-20S10. This Trinitron model, featured a single chassis, supported stereo speakers and a single composite input at the back. Additionally, it included a lone headphone output on the front panel. Performing an RGB mod on this set was relatively straightforward, as there was an unused analog RGB input available that I could easily utilize.

The RGB image showed a minor underscan, which was not noticed in the composite input. To address this, I performed a reflow on the board and replaced all capacitors in the horizontal/vertical deflection and video sections. Additionally, a capacitor on the neck board was also swapped out. While most capacitors were technically within specs, some showed slight drifts in terms of ESR. None of the above helped with the RGB underscan situation, but it definitely improved the quality of the image. I didn't spend more time fixing the underscan issue.

# 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

# Service manuals

• Sony KV-20S10 Service Manual
• Sony CXA1465AS Datasheet

# Specs

# Sony KV-20S10

• Manufactured: October 2001, Mexico
• NTSC, 60 Hz
• Chassis: BA-1
• Tube: A51JUH51X
• Jungle Chip: CXA1465AS
• Audio: Stereo

# Schematics

# Service Manual Schematics

# RGB mux diagram

# Performing the mod

You can't ask for a more straightforward RGB mod.

Fortunately this chassis doesn't require any muxing. You can pass R, G, B through a 0.1uF, 75ohm terminated wire directly to the chroma IC301. Blanking (Ys) can be fed through a 1kΩ + 0.7V didoe to pin 15 of the chroma.

# STEP 1: Free the RGB inputs

• Remove the R325 ground resistor (10kΩ) from the board.
• Carefully cut the traces on the board to ensure that the R, G, and B traces are no longer connected or shorted together.
• Make sure R, G and B are not connected to the ground either.

Cutting traces is the best approach and can be easily reversed back if needed.

# STEP 2: Connect RGB wires

See picture below to see where R, G, B wires should be connected. They are connected directly to the chroma IC. Red, Green, Blue lines are exposed on chroma pin 16, 17, 18 respectively. Since the gap here is really small, take care when soldering the wires.

# STEP 3: Connect blanking

See picture below and reference the mux diagram above to connect the blanking. Inductor leg closer to the OSD was lifted and a diode was added (pay attention to where the stripe is pointing). Blanking was then injected in the middle.

# STEP 4: Connect Sync, Audio and Ground

Sony KV-20S10 supports stereo. Therefore, audio left and audio right were wired as below. Suppose your BA-2 board only supports mono, you can twist both audio left and right and connect it to the mono audio input. 1 KkΩ audio resistors on the mux board will ensure right and left channels are mixed properly.

Sync wire (yellow) should be connected directly to the composite input.

Black wire is the common ground wire. With the latest 1.2B/1.2C PCB design you can leave both purple and orange wires floating or connect them to ground.

# STEP 5: Build your mux board (using the micro RGB board)

Below mod uses the RGB mux board. However, it is optional for BA-1 chassis. Using the mux board makes the mod neater and easier. Please note for this mod, 0.1uF caps were used in place of R4, R5, R6 resistors.

Buy your RGB mux board with the necessary parts to complete this modopen in new window

Caps were used on the mux board instead of RGB inline resistors.

Buy your RGB mux board with the necessary parts to complete this modopen in new window

# STEP 6: Attach the female SCART connector to TV

I decided to mount the SCART connector on the top part of the input cavity.

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?

# Service Menu

On the remote, press keys in this sequence DISPLAY, 5, VOL +, POWER

1 and 4 to select 3 and 6 to adjust

MUTING, ENTER to write to memory.

# Pictures

# Mux overlay

# Games

# Patterns

RGB Grid

Composite Grid

RGB SMPTE

Composite SMPTE

RGB Colors

# Set

Tube - A51JUH51X

Full Chassis

Neck Board

Chroma

OSD

Flyback

Open Back

# Capacitors

# Service Menu Settings