[TinCanAlley]

Originally Posted by Username1

"" So let me make sure I get this correct. With the HOT removed I will be able to connect my 10x probe to the collector lead of the HOT socket?

Will the waveform I get be enough to see the ringing if it exists? ""

The horiz. output transistor, like the horiz. output tube, drives the next stage, the horizontal output transformer, high voltage transformer. The pulse at the base of the transistor turns it on and off quickly, making pulsating dc, the quick turning on and off, the transformer responds to as if it was AC, making the high voltage on the output side (secondary). The collapsing magnetic field on the "off" state of the HOT will also develop a high voltage spike on the primary, (thats the transistor's side) that spike can kill your scope, and most meters if you try to measure it. So normally, you don't try. With the transistor out, the part of the circuit making the bars is partly, mostly disabled, not developing the bars. Also since the transistor is not driving the transformer, only the B+ should be on the "C" leg of the transistor, no wave shape to speak of.... No high voltage either. Think of this part of the circuit like the coil, and points in your car, or electronic ignition if you want to think of it like that.

Removing that transistor, is done mostly to see if the signal, and voltages are correct at the base, if its a NPN and the base is too positive, it will overdrive the transistor, burn it out or the horiz. transformer.

You could just put a 1 amp fuse in line with the "C" or "E" of that transistor, less expensive than a transistor.....

Check your Horiz Transistor:

http://www.youtube.com/watch?v=REW2lF0sb74

The transistor doesn't have the built-in damper diode. When I test it (like in the video), the diode function of my DMM beeps in any combination telling me there's continuity between all. The number are 009 and 002 on the display.