Ass you have it our of circuit, start by checking the DC resistance of all its windings to confirm there are no open circuits. Looking at the photos, from the dimensions and wire gauge one would expect resistances of tens or hundreds of ohms. Then check the transistors and the three diodes, and check R41-R43. Check the ESR and capacitance of electrolytics C24, C26, C27 (or replace if you don't have an ESR meter and cap meter). If no faults are found, put it back and measure the voltages in the part of the circuit to the right of T1 on the schematic, at each component pin and look for any discrepancies that may indicate a cracked track or dry joint. If you've got a scope, check the signal at the base of Q9 when DMMP transitions from high to low to see if its attempting t start oscillating.