Avt275 power issue

Discussion in 'Marshall Amps' started by Olddogmike, May 23, 2020.

  1. Olddogmike

    Olddogmike New Member

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    Just got hold of a Valve state AVT 275, but if does not show any power, before I pull the unit apart, any clues where to look first?
     
  2. pedecamp

    pedecamp Well-Known Member

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    Check the fuses.
     
  3. Olddogmike

    Olddogmike New Member

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    Can't see any external fuse holder, must be inside . I will pull the electronics out tomorrow.
     
  4. Olddogmike

    Olddogmike New Member

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    After inspection, I found the fuse before the off/on switch has blown. It reads 250v T2Al , I assume that this is a fast acting 2amp fuse. Correct me if I am wrong as I don't want to put the wrong fuse to replace the blown one. I appreciate this may not be the main problem, but its a start, and I can go on from here knowing its more than a 5cent fuse.
     
  5. South Park

    South Park Well-Known Member

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    You may have a shorted transistor .
     
  6. Olddogmike

    Olddogmike New Member

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    Yes its not the fuse, it blew straight away when I replaced it.
     
  7. Olddogmike

    Olddogmike New Member

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    The trouble with these older amps is that it could cost more than its worth unless its something basic. Techs charge big time if it can't be fixed immediately.
     
  8. Olddogmike

    Olddogmike New Member

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    I took it to a local nerd who claims he works on Marshall amps only to be told it was unfixable, fortunately he has decided not to charge me. As an ex Radio Shack (Tandy Electronics) manager, I was of the opinion that unfixable doesn't exist. I am going to take it to an authorised Marshall service shop an see what their opinion is. Might cost a bit more though.
     

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