JVC C-13110

JVC C-13110 RGB mod

This tutorial covers the RGB mod for JVC C-13110. Looking through the service manuals these instructions should also work for other JVC models (AV-13810 / AV-20810 etc.)

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: August 2000, Mexico
NTSC, 60 Hz, 60W
Chassis:
Tube: JVC A34KQW42X
Jungle Chip: TA1242N
OSD Chip: M37272MA

Schematics

Followed the specs from JVC C-20810. The jungle chip used in C-13110 was the same. Resistor values might be different. Measure what's on your chassis.

Prepare the mux diagram. If you are building your own circuit, this diagram should help

Calculating the RGB external resistor value

From the M37267M4 (OSD) chip datasheet we know the RGB high voltage is 2.4V.

Let's now calculate the peak-to-peak voltage on the RGB lines that is sent to the chroma chip.

Now that we know the expected peak-to-peak voltage by TA1242N (chroma) chip is 0.5V, let's calculate the RGB resistor value needed.

0.5 x (3900 + 75) - (75 x 2.4) / (2.4 - 0.5) = (1987.5 - 180) / 1.9 = 950Ω

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 the following components

Remove the following components. RGB resistors to the ground. Measure twice and mark before you remove.

R738 (1 kohm)
R740 (1 kohm)
R742 (1 kohm)

STEP 2: Connect RGBs, Blanking and Audio

This TV doesn't have a schematic to show this on a diagram. But, the picture below shows where the wires should be soldered. R, G, B wires should be soldered to the -ve terminals of the C801, C802, C803 capacitors respectively.

Blanking wire can be attached directly on Pin 14 of the chroma chip.

Route the wires through the hole

Audio and ground wires

STEP 3: Build your mux board

Below 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 precalculated resistor values.

Buy your RGB mux board

STEP 4: Attach the female SCART connector to TV

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?

You need the JVC branded remote to get into the service menu. Pressing both the "Video Status" + "Display" buttons together on the remote brings up the service menu.