Tascam 302 does not power up, turn on

Discussion in 'TASCAM DIY Repairs and Mods' started by Chizelwombat, Mar 23, 2021.

  1. Chizelwombat

    Chizelwombat New Member

    Mar 2021
    Tascam 302
    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?
  2. SkywaveTDR

    SkywaveTDR Well-Known Member

    Feb 2014
    Chicago area
    Teac, Tascam, Sony
    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.