SMD stands for surface mount device and if you repair LCD monitors you will come across a lot of SMD components. CRT monitors rarely use SMD, so it’s pretty easy to figure out the value of the components. In this article, I am going to talk about the SMD resistor code and how you could calculate the values. This SMD resistor code is different from the normal resistor color code (color bands) you’ve seen on electronic circuit boards. Surface mount resistors are much smaller than regular carbon film resistors and because of this the numbers and letters have been stamped or printed on top of the component.

Those numbers and letters have meaning and you could use them as information to find out or calculate your desired resistor values. Sometimes resistors are designed very small until we have difficulty reading the code. By using a magnifying glass, we could easily read the resistance codes.

There are two types of surface mount resistors used on an electronic circuit board: the 3-digit and 4-digit SMD code. The first two digits represent the two digits in the answer. The third digit represents the number of zeros you must place after the two digits. The answer will be in ohms. For example: 104 which means 100000 (4 zeros) and the final answer is 100k. Let’s calculate the SMD of 4 digits, 1182 which means 118 00 (2 zeros) and the final answer is 11.8k.

3 digit example 4 digit example R33=0.33 ohms 47000 or 47k 8202= 82000=82k

Measuring surface mount resistors is very easy with the help of a digital multimeter. Most of the time, when you directly check SMD resistors, you’ll get the correct reading even without picking up a resistor lead. But not all digital multimeters can perform this type of test. Select only the one that has an output voltage (measured at the probes) of less than 0.6 volts so that it doesn’t trigger any semiconductor devices that might give you a false reading. Once you know how to calculate the SMD resistor code and use the correct way to test SMD resistors on board, you can test many SMD resistors in the shortest possible time.