There shouldn't be any signal of note on the base of Q1234, so that's normal (it gets its signal from the emitter here). The dc levels being correct tells you that the transistor itself is likely fine, and that it's biased correctly.
The signal on the emitter will be very small (less than a VBE). To what resolution are you saying that there's no signal there? I'm betting that you weren't looking at it with sufficient sensitivity. In any case, whatever you see there, it should be the same as what you see on the emitter of its counterpart (Q1224), so probe the emitters of both transistors (or simply check continuity of the emitter connection).
Cheers
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
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On 1/21/2021 10:13, wes Bolin wrote:
I wrote a few weeks ago about no Horizontal trace on my TEK465. In the
meantime I have replaced bad caps and transistors to the point where I have
a sweep signal going to one of the CRT grids. I do not have a sweep signal
on the other grid. The good signal is on the Right Deflection Plate, and
no signal on the Left Deflection Plate. Good waveforms on B and E of
Q1224, no signal on B, E, and C of Q1234. DC voltages are good on Q1234.
I am stumped. I replaced Q1234 with another transistor but no joy. Maybe
someone can give me some help?
