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JVC AV-32D202

Brendan EddyAbout 4 minCRT RGB mod

JVC AV-32D202 D-Series CRT RGB mod

RGB Mod for JVC AC CRT televisions. Also applies to similar model numbers within the GC chassis.

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This JVC D-Series chassis includes support for analog RGB through the micom's OSD video signals. You can tap in between the OSD's output and the Y/C Jungle's input to inject your external RGB signals through a common connector such as SCART or BNC. In this guide we will be utilizing SCART, made easier with help of Sunthar's mux board, more on that later.

This mux mod will utilize the OSD circuit for RGB, Component Luma for sync, and direct connection with SCART pin 16 for blanking.

Written by Brendan Eddy (FlyingFlygon)open in new window

Reddit Threadopen in new window

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.

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

Specs

  • Manufactured: February 2002
  • NTSC, 60 Hz, 128W
  • Chassis:
  • Tube: A80QCF240X14L, A80LJF30X08-G, M80JUA061X06
  • Jungle Chip: TB1253AN (IC101)
  • OSD Chip: MN1876478JL1 (IC701)

Parts needed

  • 4 x 1N4148 diodes
  • 3 x 360 Ohm resistors
  • 3 x 75 Ohm resistors
  • 3 x 1k Ohm resistors
  • 1 x 4.7k Ohm resistor
  • 1 x SCART female port
  • Plenty of different colored wire
  • (Optional) Sunthar SCART mux board

RGB mux diagram

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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.

STEP 1: Remove grounding SMD resistors R793, R794, R795

  • R793 (330 ohms)
  • R794 (330 ohms)
  • R795 (330 ohms)

Before removing the resistors img

After removing the resistors img

STEP 2: Replace jumper wires with diodes

Replace OSD jumper wires with inline 1N4148 diodes. These wires are:

  • W296 (blanking)
  • W543 (blue)
  • W302 (red)
  • W301 (green)

Make sure the cathode end is towards the jungle as shown.

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STEP 3: Utilize the PIP header to expose RGB, Blanking and GND

At the end of these OSD lines they will connect through the unpopulated PIP connector CN003 and then enter 0 Ohm resistors before traveling to the jungle. These holes for the PIP header are convenient, as we can use them to bring the signals up to the top of the board. Standard header pins (for arduinos, etc) will fit but it's a tight squeeze. This is the route I chose. Optionally add header pins to the PIP pins 1-5. They are as follows:

  • 1: ground
  • 2: blanking (yellow wire > brown if you are using the ribbon cable)
  • 3: blue
  • 4: green
  • 5: red

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Finally, solder wires (or use quick connectors, but I avoid these due to interference/noise) to these on the top of the board, make sure they have enough length to reach the case where you will mount your external connectors (SCART, etc).

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STEP 4: Audio

Attach the rest of the wires necessary for your connector. If you're using SCART, you'll need wires for audio left and right. Regardless of SCART/BNC, you'll also need to attach a wire to the Component Luma pin for sync. Solder them at the pins like so. Make sure you use the component and audio jacks for Video 2. (I forgot to take a pic of my green wire - see the schematic for where it should go though).

Audio wires img

All wired up! img

STEP 5: Build your mux board

TV Model27D20132D202AV-32260
RGB/OSD inline resistor value (on chassis)2.2kΩ2.2kΩ2.2kΩ
Removed RGB/OSD resistor value (on chassis)330Ω330Ω330Ω
RGB in line diode method (on chassis)YesYesYes
0.1uF caps replaced (on chassis)YesYesYes
RGB termination (R1, R2, R3)75Ω75Ω75Ω
RGB inline resistors (R4, R5, R6)390Ω390Ω390Ω
Audio LR (R7, R8)1kΩ1kΩ1kΩ
Diode (R9)1N41481N41481N4148
Blanking Ground Resistor (R10)4.7kΩ4.7kΩ4.7kΩ
Blanking Resistor (R11)shortedshortedshorted

RGB mini Rev C mux boardopen in new window was used on this D-Series. The modification presented here does not utilize the benefits of the 10-pin DIN connector for convenient disconnection. However, it is strongly advisable to take this into account for your mod, as it would greatly enhance future serviceability.

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STEP 6: Attach the female SCART connector to TV

Creating a SCART cutout and mounting it is an art. There is a dedicated section for it. How to create and mount a SCART female plug?

Cut a hole in the back case for the SCART connector. Depending on if you're using a mux board, directly wired to SCART, or even using BNC or RCA, you should have plenty of options of locations. I chose above the input panel.

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Insert a cut RCA jack into the Right audio channel in order to signal to the set to use stereo audio over SCART. If you omit this step, your audio will be mono. (Don't get confused at the fact my RCA is white. It's just what I had. Insert it into the red (Right audio) jack).

Service Menu

  • Press the SLEEP TIMER key and set the SLEEP TIMER for 0 MIN
  • While the SLEEP TIMER is displaying on the CRT, do the below
  • Immediately press the DISPLAY key and the VIDEO STATUS key of the remote control unit at the same time.
  • Then enter the SERVICE MENU screen shown in figure.

Pictures

Mux overlay

RGB Overlay img

Games

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Patterns

240p pattern - Monoscope img

240p pattern - Color bars img

240p pattern - SMPTE img

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