Understanding Cathode Ray Tube Monitor Codes On Its CRT Monitors Coating

All cathode ray tube monitor (crt) have a sticker sticked on its crt coating. Those words or characters printed on the sticker are the type number of the picture tube. All cathode rays tubes, whether a monochrome (black and white) or colour crt are identified by a specific code consisting of numbers and letters. The cathode ray tube monitors codes are different from each other because different picture tubes have different characteristics. Television codes are more or less the same as the monitor codes.

For instance, most color monitor cathode ray tube has the designation code such as the M36AFA63X03. There are six meaning (parts) M/36/AFA/63/X/03 in these codes as explain below:

First Part: Application

Computer Monitor crt start with the letter "M” while for a TV crt tube, it start with “A”.

Second Part: Screen diagonal measure in centimeters (cm)

The “36” means the diagonal viewing area measure is a minimum of 36cm which refers to 15 inches picture tube, 41cm is 17 inches and so forth.

Third Part: Means Family code

The 3 letters “AFA” designate a family of crt that have similar physical and electrical characteristic. These letters are assigned alphabetically beginning with “AAA”, followed by “AAB”, “AAC” and so on. 

Fourth Part: Family number 

The number 63 means a specific tube within the family code. A different number is assigned to crt within the same family that have different neck diameters, for example a single digit would be a monochrome crt, but this two-digit number shows it is a color picture tubes.

Fifth Part: The Phosphor Type

The fifth code is the phosphor designation. The letter X here corresponds to P22 for color crt. Color monitor picture tubes can have any other single letter (excluding I, O, or W) to designate other phosphor type for various usage. For monochrome crt’s, the phosphor symbol is WW, corresponding to P4. Monochrome monitor crt also can use “WW” or some other two-letter combination (excluding I and O).

Sixth Part: The Integral neck components

The sixth code is assigned only for crt having integral neck components specification, such as the horizontal deflection yoke which connects to the horizontal deflection circuit. The specifications are only applied to a particular crt manufacturers. The primary consideration here is the winding inductance value. The horizontal yoke coils have different sensitivity such as deflection per Amp in both horizontal and vertical.

Understanding the monitor cathode ray tube type number may take you sometimes but if you begin to experiment or observed the code for every crt monitors or tv that comes in for repair, it wouldn’t take long for you to grasp the meaning of the codes.

Be careful when handling the picture tube, remember, safety have to come first. Before you start to do the crt replacement, if possible wear a goggle to protect your eyes just in case the tubes drop on the floor.