What jerks they are for charging $350 for an exchange unit or $500 for a new one, when its a $2.50 transistor that fails that anyone with basic soldering skills can change..
Its the biggest transistor in there, they tried to use the plastic housing as a heatsink - yeah, that really works... installed long leads to it - used heatsink compound and screwed it to the aluminum can case - its never going to burn out again.
Although, possibly some of the smaller transistors may blow sometimes or the one large relay in there..... still, theres less than $50 worth of parts in there all told and its certainly not rocket science to repair, classic massive 70's tracks, single layer etc...