What causes output transistors to fail?
As temperature rises in transistors (and virtually any other electronic device), they are less able to withstand stress. Under adverse conditions, they are more likely to fail when hot. All else being constant, lowering the impedance of the load on the amplifier will cause the output current to increase.
How do I know if my transistor is blown?
Connect the red probe in turn to each of the three leads. If the other two leads don’t give the same reading when touched by the black probe, the transistor is PNP and it is bad. Multimeter tests determine if a transistor is blown (open or shorted) and provide a rough estimate of the transistor’s ability to amplify.
How do you test a transistor output?
Hook the positive lead from the multimeter to the to the BASE (B) of the transistor. Hook the negative meter lead to the EMITTER (E) of the transistor. For an good NPN transistor, the meter should show a voltage drop between 0.45V and 0.9V. If you are testing PNP transistor, you should see “OL” (Over Limit).
What causes a transistor to short?
In the case of a transistor, the component is made to act as either a switch or an amplifier of electric current — as a result, a transistor’s failure can lead to electrical shorts and electrical spikes, which in certain environments can be catastrophically dangerous.
How do transistors fail?
When a diode or a transistor fails, one of two things usually happens: A junction (or junctions) go short circuit (its resistance becomes very low or zero). A junction (or junctions) go open circuit (its resistance becomes very high or infinity).
Can I test a transistor in circuit?
Potentially faulty transistors can be tested with a digital multimeter, but the type of transistor will determine the type of test used. If testing a Junction Field Effect Transistor, or JFET, you will need to use two 1000-Ohm resistors in addition to the multimeter.
What are output transistors?
Output transistors are added to provide extra current to drive a speaker. Large output transistors only have a small HFE current gain, therefore driver transistors are placed in front of the output transistors to increase to total current gain to approx 200.
Why does my amp not work?
If the Amp Doesn’t Power On at All To turn on, the amp needs power at both the remote and power wires, in addition to a good ground. If the remote turn-on wire doesn’t have power, your amp won’t turn on. If it doesn’t, check for any inline fuses and verify that the wire isn’t loose, corroded, or shorted out somewhere.
Why is horizontal output transistor in CRT monitor get shorted?
There are many reasons why the horizontal output transistor (HOT) shorted in CRT Monitor. Here are the possible cause: HOT have life span-it can work for many years but out of a sudden it can just go shorted. Replacing only the HOT solved the probem!
How do I know an output transistor is bad?
It is a Planet Audio 4 channel car audio amp. From some quick Google searching, it looks like I should be able to find replacement transistors pretty easily. As to how I know an output transistor is bad, I had an electronics place try to fix it before and they said that it had a shorted output transistor, but they couldn’t find the ones it needed.
Can a transistor be shorted from 2 legs?
If any are shorted (~0 ohms between any 2 legs of any individual transistor), they will likely be shorted from leg 2 to leg 3 but you should check 1-2, 1-3 and 2-3. Check all of the transistors individually.
Is it OK to read 0 ohms between transistors?
This is generally only viable for audio output transistors. Generally, when one power supply FET shorts, all will fail and all will have to be replaced. Above, it was stated that you shouldn’t read anything near 0 ohms between the legs of any individual transistor. This is the case for MOST transistors.