Tascam 302 does not power up, turn on

[Chizelwombat]

Hey guys. I grabbed this Tascam 302 unit for $15 and its clean inside and out but does not power up at all. I checked the power button and voltage selector on the back and they were good. I measured the voltage out of the power transformer and it read 18.6v DC. The schematic I looked at said it should be 12v but maybe 18v is ok since nothing is on and there are no loads. I removed the main PCB and the other two and they are all squeaky clean on both sides. No bulging caps or anything. What should I look at next?

 

[SkywaveTDR]

Like the other post suggests, get a DVM and go measuring voltages. As much as you might not like it, you are going to have to do the same as a Technician who works on these- exactly the same but maybe not as fast as he has a lot of stuff in his head programmed from many year experience.
Out of the transformer it goes to diodes which may comprise a bridge rectifier. Some time this is in the shape of a square with 4 leads- If a diode or two are out then no DC to go to the large filter caps. Measure filter caps as they might be shorted. I can only download a SM on the Mk II there are on that fuse resistors FR2, FR3 and regulators 78M05 but if you don't know electronics this will not be of any good to you.