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Sony KV (BA-4D) 27S42 YPbPr

Sony KV (BA-4D) 27S42 YPbPr

SuntharAbout 3 minCRT RGB modCRT component modKV-27S42KV-20S42KV-20S90

Sony KV-27S42 YPbPr Component mod

If you're looking to get the most out of your Sony KV-27S42 Trinitron, you may want to consider modding it for RGB and component output. This guide will show you how to do just that.

Shmups Referenceopen in new window

Sony BA-4D RGB Mod

Instructions below should also apply to these models:

  • KV-13M42
  • KV-20M42
  • KV-20S42
  • KV-20S43
  • KV-20S90
  • KV-27S42
  • KV-27V42
  • KV-27S46
  • KV-27S66
  • KV-35S36


CRT safety


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



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.


Service manuals


Sony KV-27S42

  • Manufactured: September 1999, Mexico
  • NTSC, 60 Hz - 90W
  • Chassis: BA-4D
  • Tube: A68LML50X
  • Jungle Chip: CXA2133S/CXA2133BS
  • OSD Chip: M37273MF-255SP


Sony BA-4D chassis schematics

YPbPr component mod diagram

Sony BA-4D chassis YPbPr diagram

Performing the component mod

This mod is farily straightforward. Except there are few points to keep in mind.

STEP 1: Remove components and add capacitors

Remove 0.01uF caps C380, C381, C382 and populate C371, C372 and C373 with 0.01uF caps. It's convenient to just move these ground capacitors over to the empty spots.

Sony BA-4D chassis remove and move caps

Attach 5V to the No Connect(NC) pad through 1kΩ resistor Sony BA-4D chassis remove and move caps

YPbPr, Blanking and Ground connections Sony BA-4D YPbPr, blanking and ground

STEP 2: Switch for component blanking

Drill holes and attach the YPbPr connectors and add a switch for blanking. I didn't have a SPST switch, so ended up using something fancy.

Sony BA-4D YPbPr connector

SCART and YPbPr Component can easily co-exist on this CRT Sony BA-4D YPbPr connector

STEP 3: Adding 75 ohm termination

Add 75Ω termination resistors to Blue and Red connectors.

Connect Green with S-Video's Luma pin. Make sure grounding wires are all connected properly

Sony BA-4D YPbPr sync and ground

Finished mod

Audio for YPbPr component goes through the standard Left and Right Audio along with Video 1 input. Sony BA-4D SCART and YPbPr connectors

Below picture is a bit blurry, but you get the idea Sony BA-4D SCART and YPbPr connectors

Reducing interference

Sometimes you might notice micro interference in the video signals. This is expected. To reduce it, try the following.

  • Use diodes in-line for RGB signal
  • Make sure your blanking wire is connected after the diode that feeds into the chroma chip (see diagram)
  • Try routing most of the cabling below the PCB
  • Keep the ribbon cable short
  • I really didn't find any difference in interference in using shielded vs non-shileded cables. Therefore, this is optional.

Getting into the service menu

  • Turn the set on and then put into standby
  • Press the Display, 5, VOL + buttons in sequence
  • Turn on the CRT and you should be in service mode
  • Use buttons "1" and "4" on the remote control to navigate the service menu
  • Use buttons "3" and "6" to adjust the selected data

Pictures of the mod

Games (KV-27S42) - Component

Wii - Just Dance Sony BA-4D YPbPr Component Wii

Wii - Rayman Origins Sony BA-4D YPbPr Component Wii

Wii - Call of Duty Sony BA-4D YPbPr Component Wii

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