Sharp 27F640

# Sharp 27F640 CRT RGB mod

This tutorial covers the RGB mod for Sharp 27F640.

View full CRT details and more mod examples →open in new window

# Contributors

Thank you to everyone who contributed to this guide:

• Matt Rossopen in new window — contributor, CRT specs from CRT Database.

# CRT safety

READ THIS BEFORE CONTINUING

# Plan of attack

READ THIS TO PREPARE

# Manuals and Datasheets

• Sharp 27F640 Service Manualopen in new window
• Toshiba TB1253AN Datasheet (Jungle)open in new window

# Specs

• Year: 2004
• Format: NTSC
• Chassis: GB-3U
• Tube: Thomson A68ELH011X
• Jungle Chip: Toshiba TB1253AN
• OSD Chip: IXA418WJ
• Screen Size: 27"
• Inputs: Composite, S-Video, RF, Component YPbPr

# RGB mux diagram

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

# Performing the mod

You might want to use 220ohm termination on R1, R2, R3 if the vibrancy of the image is lacking.

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.

• R806 (680Ω)
• R807 (680Ω)
• R808 (680Ω)

# STEP 2: Connect RGBs, Blanking and Audio

# STEP 3: Add diode to the blanking

Find a way to introduce the diode such that current from external input doesn't flow to the OSD IC.

# STEP 4: Build your mux 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 calculatoropen in new window to play with your own values.

Buy your RGB mux board kit

# STEP 5: Attach the female SCART connector to TV

# Pictures

See more photos and contributions →open in new window