[FONT="]Hi Steve,[/FONT]
[FONT="]Thanks for your reply.[/FONT]
[FONT="]Because I'm a rookie in electronics, trying to learn and understand it while I'm repairing, for the second time, my own LCD TV. The first time it was quite easy; 4 bulged e-caps on the power supply board. I replaced them and BAM! Problem solved. But, this time, it's a bit more tricky. So, I've done some voltage tests to try to find the problem's source. I've found a point where the voltage seems too low. Guess where, at the output of a transistor. Hence, my initial question to find out if the transistor can be defective or not and if I should remove it for further investigation. So, because I'm a rookie, I simply do not understand the terms "potential collector current" and "VCEsat". So, while I was searching the meaning of those terms, on the Internet, the following calculation caught my attention.[/FONT]
[FONT="]V(base) = V(input) * ((R2 / (R1 + R2)) = 5v * ((47k / (47k + 47k)) = 2.5v[/FONT]
[FONT="]V(emitter) = V(base) / 0.7v = 2.5v – 0.7v = 1.8v[/FONT]
[FONT="]I(emitter) = V(emitter) / R(emitter) = 1.8v / 47k = 0.000038[/FONT]
[FONT="]I(base) = V(source at collector) / (R1 + R2) = 5v / (47k + 47k) = 0.000053[/FONT]
[FONT="]I(collector) = I(emitter) + I(base) = 0.000038 + 0.000053 = 0.000091[/FONT]
[FONT="]V(drop at collector) = I(collector) * R(collector) = 0.000091 * 1k = 0.091v[/FONT]
[FONT="]V(output) = V(source at collector) – V(drop at collector) = 5v – 0.91v = 4.9v[/FONT]
[FONT="]Is it what you tried to explain, I mean, is it the way to calculate a transistor's output voltage?[/FONT]
[FONT="]Thanks for your time.[/FONT]