NAD 2140 Amplifier popping fuses

cdn5003
cdn5003 Posts: 144
edited September 2011 in Troubleshooting
I picked up an NAD 2140 at a garage sale that has been sitting unused for awhile I guess. When I plugged it in the lights blinked and the fuse popped. I went to Radio Shack and got 4 more 4A 250 fuses, I just tried two of them and they both popped right away also.

How should I go about troubleshooting this? I don't know a lot about electronics so any help would be appreciated.

I took the cover off and looked inside a bit but nothing caught my eye. I can post pics if that would help diagnose.
HT Setup: Onkyo 706; Rotel RB-1075; Rti A3; Csi A6; Fxi3's

2 CH: Squeezebox Touch; Dared SL-2000a; GoldenEar Triton 5 or Lsi9's; Parasound 2125; SVS SB12-NSD; Music Hall DAC 25.2
Post edited by cdn5003 on
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Comments

  • [Deleted User]
    [Deleted User] Posts: 7,658
    edited September 2011
    Hello,
    The standard procedure is to look at the complete schematic and see how the power supply is connected to the circuitry. Then you separate the power supply from the circuitry and substitute a resistor load that approximates the load the power supply normally sees. By connecting the amp to a variable AC supply that shows current draw, you slowly increase the incoming AC and watch the current draw. If the power supply seems to be coming up to power with the load resistor then it is probably okay. If not then you have a power supply problem, blown regulator, shorted cap, etc. If the power supply seems operating then you have to look at the circuitry it is driving.
    So, the first step is to get a schematic of the amp's circuitry.
    I hope this gives you a beginning point.
    Regards, Ken
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