HP 8642A Signal Generator Output Clipping

[sfoster]

I just picked up an HP 8642A for doing AM/FM tuner alignments. Yes, it's a bit of overkill but the price was right. I'm also using a Sencore SG-165 for external modulation and an HP 334A to measure distortion. All was working well, though I have an issue with the 334A balance control...another thread perhaps. While working, the output of the generator was shorted due to a homemade banana plug adapter for the 334A input. The correct one has been ordered. Now I have clipping at the top of the waveform below 5kHz. This decreases with frequency but the sinusoidal is not symmetrical. The modulation and 10 mHz output look good. Also when I perform the Instrument Level Self Test, after a few minutes the display is "No Messages". This means all modules have passed.

Perhaps there was no circuit protection for my sloppiness. Attached is the output on my scope of 1kHz. I have seen this before on an audio receiver when an output transistor's emitter resistor goes open.
I have all the manuals and am starting to go through them, but this unit looks quite daunting compared to what I'm used to. Any thoughts for troubleshooting are appreciated.

Thanks -Steve