Philco Safari Vertical Foldover issue

[goat1981]

Originally Posted by Electronic M

If all R'r and C's have been replaced then it's either Yoke, transformers, or transistors.

Partial failure is possible with early transistors. I have seen early 70's transistors develop weird problems so earlier ones are more suspect.

One other possibility is a problem baked into the factory design....

Thanks for the reply.

I checked the resistance of the transformer windings, and they all seem to be in spec. Not too sure about the yoke - even though those resistances also check out, I am sure other factors could be at play there.

I suspect it's the vertical output transistor, as that's where the voltage readings are off. I may try the NTE 121 transistor, but I am wary about 'universal' replacements, especially to replace such an early transistor that was specifically designed for this TV...

I know vertical linearity *can* be good - I have seen a couple of sets play (i.e. the Safari that Bob Anderson restored on YouTube) that have very little vertical distortion.

I would have asked to buy that transistor from you, but from the pictures you sent earlier, it looked like it was missing from your parts chassis.

Thanks again for all your help. Any other suggestions are very welcome. :-)