Ok. First do a visual inspection … anything look burnt ?… any electrolytic capacitor look bad (do the tops looking bloated)? Anything loose?
No .. start checking the power supply voltages. Linear supplies are usually fairly simple. Mains into primary transformer winding with 1 or more secondary windings out (each supplying an AC voltage). Each winding goes to a rectifier (one to four diodes depending … sometimes in a single package) and then usually to a storage cap. At this point it’s a DC voltage with a bit of 60hz ripple. After this there might be additional circuitry but for now we just want to know how many secondary windings and measure the DC voltages at those caps. Your meters black lead goes to ground (try the case or heat sink) and then the meter’s red to one side of each storage cap or the other (one is ground the other should give a reading). If you have trouble… take some pictures and either post them or pm me for my email. Have fun.
