Sunn 1200S PA distorting

[Nyqusit5]

Hi,
I am currently working on a Sunn 1200S. The PA is faulty. Several O/P transistors were shorted so I replaced all of them. With the amp powered up through a bulb current limiter and fed with a sine wave, I get a distinctive distortion at one point of the sine wave on the output of the PA (signal is good at its input). I tend to think one of the o transistors is faulty even though I have replaced them. What do you think?
At very (very) low settings of the master volume control, the output is undistorted.

Included are the distorted wave on the scop and the 1200S schematic.

[52 Bill]

Have you tested all of the transistors in the power amp including the drivers?

Have you tried powering up the amp with no speaker load and without the limiter?

[Enzo]

And all those output transistors have resistors associated with them, check all those resistors for opens.

[Nyqusit5]

Thanks.
The amp is tested without a load at the moment. The signal you see on the scope is without a load. With a load, the signal drops and distorts significantly.
I'd like to get a clean output signal before I test the amp without the limiter.
I have also checked the drivers and the resistors but they seem ok.

[Jazz P Bass]

If the amp is Not drawing excess current at idle, ditch the limiter.

[Nyqusit5]

The output is identical without the current limiter.
I am going to try replacing Q31 to Q34 again given the location of the distortion. R216 to R219 all read fine.