______________________________________________________________ Solid State Power Supplies
You may check a capacitor suspected of being open by disconnecting it from the circuit
and checking it with a capacitor analyzer. You can check a capacitor suspected of being
leaky with an ohmmeter. If it reads less than 500 kilohms, it is more than likely bad.
However, capacitor troubles are difficult to find since they may appear intermittently or
only under operating voltages. Therefore, the best check for a faulty capacitor is to replace
it with a good one. If this restores proper operation, the fault was in the capacitor.
Resistor Troubles
4-144. The following (also see Figure 4-54) are the three things that can happen to a
resistor:
It can open (number 1).
It can increase in value (number 2).
It can decrease in value (number 3).
Figure 4-54. Resistor Troubles
Remember to use an ohmmeter to check possible resistor troubles. Make sure no parallel
circuit is connected across the resistor you wish to measure. When you know a parallel
circuit is connected across the resistor or when you are in doubt, disconnect one end of the
resistor before measuring. The ohmmeter check will usually be adequate. However, never
forget that sometimes, intermittent troubles may develop in resistors as well as in any other
electronic parts.
4-145. You may observe different problems that have not been covered specifically in this
chapter. However, you should have gained enough knowledge to locate and repair any
problem that may occur.
23 June 2005
TC 9-62
4-47
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