April 25, 2011

Testing Resistors with an Ohmmeter

Resistors condition can be checked using the ohmmeter function of the multitester. The possible troubles of resistors are open, increased resistance value and decreased resistance value. Below are the guides that you should follow to test the condition of the resistor.

  1. Switch off the unit under test.
  2. Disconnect one terminal of the resistor from the printed circuit board (PCB). Be careful when disconnecting the resistor from the circuit, recklessness may result in breaking the printed circuit foil or the resistor itself.
  3. Set your ohmmeter to the appropriate range. When checking resistors of high resistance value, adjust the ohmmeter to the highest range.
  4. Should the meter reading is within the tolerance values the resistor is good.
  5. Should the pointer needle of the multitester did not deflect, the resistor is OPEN.
  6. Should the meter reading is higher the maximum tolerance value; the resistor has INCREASED ITS VALUE.
  7. Should the meter reading is lower than the minimum tolerance value; the resistor has DECREASED ITS VALUE.