Sony (AA-1) KV-27V55
Sony (AA-1) KV-27V55 CRT RGB mod
This tutorial covers the RGB mod for Sony KV-27V55.
View full CRT details and more mod examples →
Contributors
Thank you to everyone who contributed to this guide:
- Sunthar — contributor, RGB mod and pictures
CRT safety
Caution
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
Manuals and Datasheets
Specs
- Manufactured: USA (1994)
- Chassis: AA-1
- Tube: Sony Trinitron A68KZJ50X
- Jungle Chip: Sony CXA1465AS
RGB mux diagram
Prepare the mux diagram. If you are building your own circuit, this diagram should help.
Schematics
Really simple RGB mod is possible on this chassis. We will be disabling Closed Caption Decoder (CCD) and leveraging the analog RGB inputs used to feed our external RGB signal.
Let's review the block diagram and schematics first.
Chroma CXA1465AS - Block Diagram 
If you look at the block diagram, analog R, G, B inputs at pins 16, 17, 18 are what we are going to be harnessing.
Chroma CXA1465AS - Schematics 
The above schematics shows the R, G, B, Blanking signal going from the CCD chip to the CXA1465AS chip. Pink circle shows the caps C315, C316 and C317 that we will be removing.
Performing the mod
Remove capacitors C315, C316, C317 on the M board and inject R, G, B to the positive terminals. Isolate blanking by removing R165 and inject blanking there.
- Chroma Chip: CXA1465AS (M-Board) - IC101
- Closed Caption Decoder (CCD) Chip: Zilog SL1635 (M-Board) - IC150
RGB mod
RGB mod on Sony KV-27V55 is similar to KV-27V10. Speakers on this unit was huge compared to KV-27V10. Also, the other notable difference was the PiP board.
M 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 calculator to play with your own values.
| RGB mux board | KV-27V55 |
|---|---|
| Mux board RGB termination (R1, R2, R3) | 75Ω |
| Mux board Audio LR (R7, R8) | 1kΩ |
| Mux board blanking diode (R9) | 1N4148 |
| Mux board blanking ground resistor (R10) | open |
| Mux board blanking resistor (R11) | 4.7kΩ |
| Mux board transistor base resistor (R12) | 1kΩ |
| Mux board transistor (Q1) | PN2222A |
Compatible mux boards:
RGB mux board 
SCART port 
Back wire plugged 
Chassis, tube and more
Tube 
Chassis 
Chassis 
Back full 
Back open 
Back open top/down 
Pictures
Note: Some of the pictures might repeat.
Games
NES - Adventure Island 
NES - Alien 
NES - Alien close-up 
SNES - Megaman X 
SNES - Super Metroid 
RGB-Pi 
Sega Genesis - Alien 
SNES - Street Fighter 
SNES - Street Fighter close-up 
Atari 2600 
Fixing the Sag
A68KZJ50X tubes have a noticeable sag. This is primarily due to the heavy deflection coil. It can be mostly corrected by reseating the yoke.
Sagging - SNES Adventure Island 
Reseating the deflection yoke 
Reseated deflection yoke 
Grid pattern 
Pictures
Reference Photos
