How to find the value of burnt Resistor (by three handy methods) How to calculate the value of resistor for LED's (with different types of LED's circuits) 0R10 =0.1 x 100 = 0.1 x 1 = 0.1 Ω (4-digit SMD resistors (E24 series) 25R5 = 25.5Ω (4-digit SMD resistors (E96 series)) Below are the rules to follow to know the value of EIA-96 SMD resistors. The first two (2) digits or numbers will indicate the significant digits or numbers. The third one "Letter" is a multiplier (in Power of Ten i.e. 10^ something) and then must be multiplied by the first Two (2) significant digits. Must follow the codes in Table (1) and (2). exception values 10/11/13/15/20/75 of E24 series Size 0603 of RC/RE series 1%, 0.5% E96 Size 0603 of AR/AF/AC series 1% E96 XXX formed with 2 numerals + 1 letter Size 0603 of RT/RJ 1%, 0.5%, 0.25%, 0.1%, 0.05% E96 including values 10/11/13/15/20/75 of E24 series Size 0603 to 2512 of RC/AC series Size 0603 to 1206 of AR/AF series Size 0805 to Here, we note the equivalent resistance as Req. Figure 10.3.5: (a) The original circuit of four resistors. (b) Step 1: The resistors R3 and R4 are in series and the equivalent resistance is R34 = 10Ω (c) Step 2: The reduced circuit shows resistors R2 and R34 are in parallel, with an equivalent resistance of R234 = 5Ω. With a wide variety of ranges, the resistance of a resistor can be as high as megaohms or as low as less than 1 ohm. The EIA (Electronic Industries Association) has specified standard resistor values and classified them into E3, E6, E12, E24, E48, E96, and E192 series, which are so-called E-series. select x = 3, R = 120. That is, you use the R ranges from the next higher series, for example, E24, to determine the limits of each E12 value. Once you find the correct x value, use a lookup table for the E12 value because rounding and truncating does not always give the the exact value of the series. tFOOdl.