Test Q2,Q3,& Q4 for the proper 2 junctions on each transistor.

The Q2 transistor that’s heat sinked to the frame will have it’s leads poking thru the board. The other 2 transistors can be tested if theres enough room for the leads to touch transistor wires. The 2 junctions in each transistor should read close to the same at 7-15 ohms is common.
Sometimes in circuit test results may vary due to other components in the circuit.

Turn the 5volt pot to its minimum setting. It might be the over voltage circuit is shutting it down. Retest, has the 4,5,& 8 dc volts outputs returned? Power supply might be in need of recapping.