Looking to repair this M175 for a local. Not too familiar with amps. The CBTricks site for the Messenger schematics - states that the schematics are wrong. Doesn't matter that much, as they don't list the M175 model anyway. On the a/b/c side of the input xformer, there are two diodes that have been burned up and removed by the owner of the amp. Picture below shows a black arrow as to where one of the burned diodes was removed. On the other side of of the a/b/c xformer, the other diode was also burned and removed. Were the original diodes used 1N4001's? Any info, experience with this amp, repair tips, or usable schematic link is appreciated.