Hi James. Your meter, like mine, has a mode to test the hFE of the transistor. Set the rotary switch to hFE, plug the transistor emitter, base and collector leads into the appropriate holes for either PNP or NPN per the transistor type. The hFE value will be displayed for the test condition of base current 10microAmps and Vce 3V. Compare this value to the hFE from the transistor's data sheet.
As I explained at 45 seconds into the video, I was explaining a way to quickly and simply check to see if a transistor is shorted. I know how to use the hFE function of my meter. However, the failure mode of transistors in the electronics that I have repaired for my business have been predominately shorts in one of the junctions. It is not normally necessary to measure the Current gain ( hFE) and compare to a datasheet to determine that a transistor shorted. In this video I am giving a tip on how to "check" transistors for shorts for those that want to use my tip.
Jacky Jack I do not have a video on capacitors. Some digital multimeters have a function for measuring capacitance. Also, there are some reasonably priced capacitance testers available. I have one and it’s really handy.
Thanks for the comment. Just trying to keep it simple. You are really just looking for a short between one of the junctions. You can go to a datasheet for the particular transistor you are checking to identify B, E, and C if you need to know. If any of the junctions are shorted, then the transistor is bad. Shorting of a junction is a common failure mode of bipolar transistors.
On the good transistor 1 is base (the common lead on which two good readings were), and since the reading was with negative on lead 1, base is n, so it is pnp transistor.
You can check a transistor while installed in the circuit, but you may get a false reading. If there is a component that offers a low resistance connected in parallel with one or more of the junctions of the transistor you are checking, you will get a low resistance reading indicating a possible short in the transistor. But, if all components connected to the transistor you are checking are of high resistance, then you may be able to detect a shorted junction in the transistor. So, you can start with a check of the transistor in circuit and if it appears to be shorted, remove it and check further.
0.5 to 0.8 volts i have a 2 pin diode D501 in my fuse box under the hood , when i check my D501 Diode it is .914 V , what i like to no is that good or bad ?
Probably good. A silicon diode normally has a voltage drop of about .6 volts when forward biased. With no power to the diode measure resistance in both directions as shown in the video. Use the diode setting on your DVM. It should read high resistance in one direction and very low in the opposite.
I can be used in circuit as long as you have a schematic diagram of the circuit to know if there is a low resistance component across any of the transistor leads that would indicate a false short.
This video is very useful, dont need to buy expensive analog tester,, thank you sir from Philippines.
Hi James. Your meter, like mine, has a mode to test the hFE of the transistor. Set the rotary switch to hFE, plug the transistor emitter, base and collector leads into the appropriate holes for either PNP or NPN per the transistor type. The hFE value will be displayed for the test condition of base current 10microAmps and Vce 3V. Compare this value to the hFE from the transistor's data sheet.
As I explained at 45 seconds into the video, I was explaining a way to quickly and simply check to see if a transistor is shorted. I know how to use the hFE function of my meter. However, the failure mode of transistors in the electronics that I have repaired for my business have been predominately shorts in one of the junctions. It is not normally necessary to measure the Current gain ( hFE) and compare to a datasheet to determine that a transistor shorted. In this video I am giving a tip on how to "check" transistors for shorts for those that want to use my tip.
This is good and helpful
it help a lot but what would like to know is a low reading is good but is there a to low that could be bad and if what is the good lows you should see
Love the video. Very helpful. Do u have a video on testing capacitors? I keep getting protect mode on my receiver.
Jacky Jack I do not have a video on capacitors. Some digital multimeters have a function for measuring capacitance. Also, there are some reasonably priced capacitance testers available. I have one and it’s really handy.
thank for your time
Is that a velleman multímetro?
Yes
Good explanation, but if you mention which is base, emitter and collector can be more helpful and way better for a novice like me.
Thanks for the comment. Just trying to keep it simple. You are really just looking for a short between one of the junctions. You can go to a datasheet for the particular transistor you are checking to identify B, E, and C if you need to know. If any of the junctions are shorted, then the transistor is bad. Shorting of a junction is a common failure mode of bipolar transistors.
On the good transistor 1 is base (the common lead on which two good readings were), and since the reading was with negative on lead 1, base is n, so it is pnp transistor.
Thank you for the video
You deserve a like
But how ti check transistor if its installed on the circuit
You can check a transistor while installed in the circuit, but you may get a false reading. If there is a component that offers a low resistance connected in parallel with one or more of the junctions of the transistor you are checking, you will get a low resistance reading indicating a possible short in the transistor. But, if all components connected to the transistor you are checking are of high resistance, then you may be able to detect a shorted junction in the transistor. So, you can start with a check of the transistor in circuit and if it appears to be shorted, remove it and check further.
@@jamelectronics
You are great thanks
I will follow you
0.5 to 0.8 volts i have a 2 pin diode D501 in my fuse box under the hood , when i check my D501 Diode it is .914 V , what i like to no is that good or bad ?
Probably good. A silicon diode normally has a voltage drop of about .6 volts when forward biased. With no power to the diode measure resistance in both directions as shown in the video. Use the diode setting on your DVM. It should read high resistance in one direction and very low in the opposite.
Can it be tested on circuit or has to be off circuit to be tested?
I can be used in circuit as long as you have a schematic diagram of the circuit to know if there is a low resistance component across any of the transistor leads that would indicate a false short.
ty
Sir, why 1&3have reading am confessing about this.
Cant see the screen