Scarp the outer coating. Clean the Burnt Section of the resistor Measure resistance from one end of the resistor to the damaged section Again measure the resistance from damaged section to the other end of the resistor. Add these two value f resistances This is the approximate value of Burn resistor Just add a small value of resistance for damaged section .i.e., suppose the value of burnt resistor was 1k Ω, but you got 970 Ω. So just add 30 Ω, and you will have 1k Ω.

Method 1

Scarp the outer coating. Clean the Burnt Section of the resistor Measure resistance from one end of the resistor to the damaged section Again measure the resistance from damaged section to the other end of the resistor. Add these two value f resistances This is the approximate value of Burn resistor Just add a small value of resistance for damaged section .i.e., suppose the value of burnt resistor was 1k Ω, but you got 970 Ω. So just add 30 Ω, and you will have 1k Ω. Method 2 This method also can be used for finding the value of resistors (Also, for connected resistors in the circuit) if you don’t know about Resistance Color Coding. Connect Resistor to Multimeter and measure voltage drop across Resistor. Now measure the current flowing into the resistor. Multiply both values and you will get the wattage of Resistor (As P = VI) This Wattage must be less than the wattage of the resistor being replaced

The circuit diagram? Find the datasheet of the used components around it, hope for an application note in one of them that resembles the diagram? Make an educated guess and hope for the best? – jippie Jun 22 '13 at 13:27

@jippie am just asking whether it is possible or not?No any circuit no any other datasheet?How an educated guess? – Atom Jun 22 '13 at 16:10 1
Get experience in electronics, check datasheets and application notes, develop a feeling for how a circuit works, reverse engineer the circuit diagram that you have and try to understand how it works. Get a pencil and a piece of paper to do some calculations on. Nobody will be able to give you a cookbook style solution for it. – jippie Jun 22 '13 at 17:48