EV 7600 power amp

[bsco]

Hi.....I received a bunch of old power amps from a local sound guy......he was getting ready to give them the old "HEAVE HO"......so I picked them up before they went to the dump.....different brands......these in particular look like they are in decent shape..(one is in protect mode on one channel)......so might be worth fixing up......he did mention that these amps were plagued with a couple of common issues but couldn't quite remember what they were.....just checking here to see if anybody had any experience working on this model in the past and if anybody here knows what the issue(s) the guy was referring to......Thank you very much.....
Cheers
P.S. They must pack a fair bit of punch as the power transformer is huge......

[Jazz P Bass]

Here is the schematic: electrovoice_7600_sml.pdf