Re: Dell e152fpb no back light
Hold your horses!!! There is no need to replace anything AT THIS TIME. That may change within a few minutes. I'm going to redo the picture based on Bobdee's correction.
OK, corrected picture is attached. Here is what you should do: Set the meter to the Diode check scale - often one of the lowest Ohms scales (this applies about 2 volts across the leads). Note that each of the transistors circled in red has the letters B C E near it. Probe the pins with the leads in both directions. I suggest doing this as follows: Hold the black probe on the leg labeled B. Note the readings when the red probe is touched to C and then E. Move the black probe to C and note the readings when the red probe is touched to B and then E. Lastly, move the black probe to E and note the readings for B and then C. Repeat for the other three transistors.
A good transistor out of circuit would show open on all readings except when the red probe is on the B (base) and the black lead is on either the E (emitter) or C (collector) for the 2SC5707 and any other NPN transistor. Then it should read about .7 volts
This may not be the case with the transistor in circuit, but you should get similar readings for all four transistors. Under no circumstances should you get a reading of 0 volts.
PlainBill
Originally posted by Maluko75
OK, corrected picture is attached. Here is what you should do: Set the meter to the Diode check scale - often one of the lowest Ohms scales (this applies about 2 volts across the leads). Note that each of the transistors circled in red has the letters B C E near it. Probe the pins with the leads in both directions. I suggest doing this as follows: Hold the black probe on the leg labeled B. Note the readings when the red probe is touched to C and then E. Move the black probe to C and note the readings when the red probe is touched to B and then E. Lastly, move the black probe to E and note the readings for B and then C. Repeat for the other three transistors.
A good transistor out of circuit would show open on all readings except when the red probe is on the B (base) and the black lead is on either the E (emitter) or C (collector) for the 2SC5707 and any other NPN transistor. Then it should read about .7 volts
This may not be the case with the transistor in circuit, but you should get similar readings for all four transistors. Under no circumstances should you get a reading of 0 volts.
PlainBill
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