QSC A21 bias?

I recently picked up an old QSC A21 amplifier to rebuild, this is the schematic:

http://www.qscaudio.com/support/library/schems/Discontinued/A Series/A21-22.pdf

Anyone have the adjustment info for the bias and current limiting?

This is the first amp that I have worked on with this sort of topology. I'm looking forward to learning more on the theory of operation, since I've never dealt with the floating power supply design. QSC seems to have used it in other models too, such as the older MX series.

I've seen that clipping indicator circuit with the bridge rectifier before too, but I'm not sure how it could work like that. Where are they getting the reference point to calibrate the LED from?
 
Got the amp yesterday. Found one shorted output transistor and removed it, and the amp powers up and sounds good.

I'm contemplating whether to replace the bad transistor (SJ9092) with an MJ15016, or if I should replace all 3 SJ9092 with MJ15016. Not sure how picky the amp is about matching gain on the transistors.

Ideally I want to replace all transistors in the affected channel, but it's probably not worth the cost. I'm just going to use it on a pair of bookshelf speakers for my workshop PC.