Toshiba 27A30
Toshiba 27A30 CRT RGB mod
RGB modification showcase converted from a community support request.
View full CRT details and more mod examples →
Contributors
Thank you to everyone who contributed to this guide:
- Michael Lopez — photos and documentation
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
Service manuals
Specs
- Year:
- Chassis: N0ES
- Jungle Chip: Toshiba TA1223AN
- OSD Chip: TMPA8700CMN
RGB mux diagram
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.
| Component | Value |
|---|---|
| RGB/OSD inline resistor (chassis) | 4.7kΩ |
| Removed RGB/OSD resistor (chassis) | 1.2kΩ |
| RGB inline diode method (chassis) | Yes |
| 0.1μF caps replaced (chassis) | Yes |
| RGB termination (R1, R2, R3) | 75Ω |
| RGB inline (R4, R5, R6) | 1kΩ |
| Audio LR (R7, R8) | 1kΩ |
| Diode (R9) | 1N4148 |
| Blanking Ground Resistor (R10) | open |
| Blanking Resistor (R11) | 4.7kΩ |
Performing the mod
Remove RA25 (6.8kohm) and the ground resistor RR93 (4.7kohm) and replace RA25 with 4.7kohm removed from RR93.
Pictures
Photos by Michael Lopez's Sector
Final pattern after RGB mod
RGB image with no noise
RGB image with no noise
Image highlighting the ringing noise artifact
Image highlighting the ringing noise artifact
Plan. What ultimately removed the noise was removing RR93 (4.7k) and RA25 (6.8k). Replace RA25 with the remove 4.7k.
On the mux board add 4.7k to R10 and R11.
Make sure all the diodes are added to R, G, B and blanking lines on the chassis.
Final configuration. R10, R11 = 4.7k
