Need help with a US-4X4

Discussion in 'TASCAM DIY Repairs and Mods' started by David steines, Jul 3, 2018.

  1. David steines

    David steines New Member

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    Hi,

    I have to fix a US-4X4....someone used a bad power supply with it and blew up two diodes right at the AC input. I can't find these on internet....no cross reference or schematic anywhere. Anyone knows how and where can I find these two diodes? Here are their PCB numbers with the part number written on each:

    D47 (3548)
    D59 (PJ4356BF)

    Thanks!!
  2. SkywaveTDR

    SkywaveTDR Well-Known Member

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    Time to get a service manual for it. It says it takes 12 Vdc input so why are there diodes?
  3. David steines

    David steines New Member

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    Yeah I agree for the service manual....but where to get it? :/ ....I don't know what the diodes are for. I know some companies are using them as a protection in case someone uses a wrong polarity....but I don't know if it's the case with this unit...

    Do you know if Tascam are selling their service manuals?
  4. SkywaveTDR

    SkywaveTDR Well-Known Member

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    Well if the diode is hooked to the power in reverse then any large diode should do the job as all it is doing is conducting in a wrong connection. I would pick a 3A diode. Without a schematic and I have looked a few times now, it is hard to know what the diode(s) do. i would have to see the unit to determine what they are there for. No, I am not looking for more work as I have too much already.
  5. David steines

    David steines New Member

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    I think I'll give it a try... Thanks a lot for your help SkywaveTDR!