[TenTec] 255 Power Supply

[Dr. Gerald N. Johnson]

The transistors are wired in parallel, but that 0 resistance from base 
to one of the connections is a shorted junction in one of them. There's 
no repair possible for the transistor, it must be replaced. When you 
take them out, you can tell which is bad, but a sturdy pair isn't a bad 
investment.

.514 is about right for the forward drop of a silicon junction. OL is 
right for open. Which a junction should be one way. .000 for both 
polarities of the meter shows the shorted junction.

73, Jerry, K0CQ

On 3/12/2011 10:23 PM, Jim Anderson wrote:
> After searching Google on how to test a transistor I realized I was doing it
> wrong.
>
> Here are the new readings...
>
> On the Diode function and the black lead on the base it reads .514 on one
> terminal and .000 on the other
> With the red lead on the base it reads OL on one terminal and .000 on the
> other.
> Both transistors give the same results.
>
> On the 2K ohm scale with the red lead on the base it reads 1.2 on one
> terminal and .000 on the other
> With the black lead on the base it reads 1.1 on one terminal and .000 on the
> other.
> Again, both transistors give the same results.
>
> Thanks for sticking with me on this.
>
> Jim
>
>