Dynacord PCA2450 power amp no output on load

[Nyqusit5]

Hi all,

I have a PCA2450 Dynacord mosfet power amp for repair. Without a load, the output is pretty good (sine wave when a sine wave is applied at input), and when a load is connected, the output drops instantly to almost nothing and is distorted. This is the case on both channels.
The ballast resistors measure ok, and the power trnasistors seem fine.

Can anyone suggest a possible origin of the fault? I include the schematic.

Thanks in advance!

dynacord pca 2450.pdf

[Jazz P Bass]

Can you move back to the gate & measure that?
I guess the idea is to find out what else is collapsing.

Usually when the output fails under load, it's the drivers.

[Nyqusit5]

Thank you for your reply.
The drivers seem fine but I have found that the gate voltages are all over the place, even comparing both channels. I'll replace them and see what happens.