# Samsung TXD1973 CRT RGB mod

This tutorial covers the RGB mod for the Samsung TXD1973 CRT TV.

Reddit Thread (opens new window)

# CRT safety

DANGER

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

# Specs

# Samsung TXD1973

  • Manufactured: 1997 October, TIJUANA, MX
  • NTSC, 60 Hz, 80 Watts
  • Chassis: K1
  • Tube: Samsung A48KRD82X (This tube was used in swapping K4600 tube)

# Schematics

It's hard to find the service manual for this Samsung CRT TV. I had to stitch together this scehmatic diagram from multiple images. Although not perfect, this should be sufficient to perform the RGB mod.

# Prototyping the mod

Since this is the first time I'm modding a CRT from Samsung, I wanted to prototype the mod first. I reviewed the schematics and came up with the below plan.

The main board is fairly compact. The main board also comes off the CRT completely, if all the wires are carefully disconnected. This makes it easier to perform the mod. Please make sure to remember or take photos as you disassemble, so that you can reassemble the way it was prior to disassembly.

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Simplified circuit diagram that was created to perform this mod. Check the RGB theory page to find more details around how to calculate the resistor values.

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# Performing the mod

This CRT was fairly straightforward to mod. You can perform the mod on the board itself and don't need a MUX board.

# Using the stock SCART port

This CRT comes with a stock AV port that has a SCART cutout. I wanted to utilize this to give this CRT a clean look. Here is how it looks when finished.

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You will soon realize this is not as easy as it looks. There isn't that much space on the board to accomodate a SCART plug and the necessary wiring.

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# How was this achieved?

Remove the existing A/V connector.

Move some of the components to the bottom of the board to make some space.

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Create a flexible pcb that grouned the relevant pins together and allowed for routing of the wires. Flexible pcb was used, because there is not much clearance and you want this to be flexible. I'll let the pictures below explain the process.

Check the placement of the flex pcb img

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Make your own flex ribbon board at OSHPark (opens new window) or buy it here img

Attach all the necessary wires img

Flush cut the SCART pins and solder to the flexible pcb. img

Insulate the SCART adapter with some electrical tape img

Insulate the main chassis img

Insulate more img

SCART soldered img

SCART side view img

Removed R204, R205, R206. Used the existing vias to connect R, G, B, blanking and ground.

  • R, G, B (red, green, blue wires)
  • Fast Blanking (brown wire)
  • Ground (black and purple wire)
  • Ground (leave the organge wire disconnected)
  • CSYNC - directly connect the CSYNC pin to the board and solder it.

RGB wires needs a triangle formed between 75 ohms and 1.2 kohms. 75 ohms goes to the grounding side. 1.2kohms faces the 0.1uF capacitors. img

Blanking wire (brown) needs a didoe inline. Replace the existing blanking inline resistor with another diode and put a 6.8 kohm resistor after the diode. img

Bypass the CCD to ensure the video is not dark img

Audio wiring (grey, white). Put two 1 kohm resistors for both left and right wires and connect them both to the board img

Ground wiring (black, purple). Twist them together and connect them to the below location.

Connect CSYNC to this location img

WARNING

Use heat shrink tubes to prevent shorting. img

All wired up! img

How the back of the TV looks after buttoning everything up. img

TIP

Connector will be a bit wobbly. However, once the back cover is put back in place and closed up with screws, connector should stay strong. Please be mindful not to push the connector in too tightly and break the connector. Understand the limitations of this mod and possibly use an extension not to damage the SCART connector. SCART closeup. Back cover holds connector in place. img

# Adjustments, Games and Patterns

Colors don't really pop on this TV for some reason. But, it has a nice overall look that will give an awesome nostalgic experience. Modding this TV is really straightforward. Image was a bit washed out, right after injecting the RGB signal without touching anything on the CRT.

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Let's see what options we have to make this look better.

# Adjusting the flyback screen brightness

After decreasing the screen brightness on flyback, colors seemed to be much better. OSD menu overlay was also visible. img

# Service Menu

While in Standby mode, using the remote MUTE > 1 > 8 > 2 > POWER should bring you to the service menu.

Default settings for this CRT img

Adjusted values img

HS - Horizontal Shift was adjusted to center the RGB image. RC - Red Cutoff and GC - Green Cutoff was adjusted to 0 and 21 respectively to reduce the redness and balance the colors. YMMV.

# Games

Spiderman SNES img

Super Mario World SNES img

MegamanX SNES img

# Test patterns

Monoscope img

# Remote control

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There are quite a few prominent folks who pioneered RGB mod on this TV. Links to their content below

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