Pedal died running it at 18V. Tech Repair Q.

Discussion in 'Effects, Pedals, Strings & Things' started by RockStarNick, Feb 13, 2012.

  1. RockStarNick

    RockStarNick Supporting Member

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    So for the last month, I've been running my MXR CAE401 clean boost at 18V. (The instructional manual says that this is TOTALLY fine, and allows for increased headroom).

    This weekend before a gig, poof. I get nothing. No lights, and when I switch the pedal ON, I get a drastic reduction in volume, and a very thin tinny sound.

    Any ideas what could have been fried inside?

    I'm very confident with soldering and working on PCBs.

    I'm going to open this sucker up tonight to take a look.
     
  2. vanguard

    vanguard Member

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    there's prob a protective diode or resistor at the input that fried.
     
  3. RockStarNick

    RockStarNick Supporting Member

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    Hmm. OK.

    I've got a cap tester, and a digital MM. I'll start poking around to see what I can find. I'll post pics later on.
     
  4. Montez

    Montez Member

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    Check your E-caps they are the most likely die of over voltage. C1, C4, and C5. If you do need to replace them, use Nichicon Fine Gold caps with a step higher voltage rating.
     
  5. jb4674

    jb4674 Member

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    What kind of power supply were you using?
     
  6. RockStarNick

    RockStarNick Supporting Member

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    Voodoo Labs PP Iso5. I don't use anything but VooDoo.
     
  7. Peteyvee

    Peteyvee Premium Platinum Member

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    Did you measure the output from the Voodoo to see if that isn't the problem? Did you try another power supply, like a wall wart? How about trying it on batteries? Is the MXR under warranty? If it is, get an RA and send it back to them. Those are a few of the things you should try before opening it up and they're called "troubleshooting" or "isolating the problem". But hey, it's your pedal...
     
  8. RockStarNick

    RockStarNick Supporting Member

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    Sorry. Should have noted in the original post that I've tried all of these. Everything checks out on my VooDoo. Wall wart power doesn't work. Batteries don't help either.

    I bought the pedal used, so it's not under warrantee. And a factory repair would cost me just about as much as the pedal itself did.

    And yes, I'm familiar with "troubleshooting" ;)
     
  9. Montez

    Montez Member

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    If you do replace the Ecaps make sure they are oriented correctly as they are polarized. If you have the pins backwards, you will blow them out when you power it up.
     
  10. jkokura

    jkokura Member

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    If I remember right, those pedals use some SMD parts. I hope you're able to get it fixed.

    My first guess is something either in the caps or in the diodes as mentioned above. I or many other guys on here can help. I'd need some high quality pictures of both sides of the PCB and some voltage readings if you're interested in having some help.

    jacob
     
  11. RockStarNick

    RockStarNick Supporting Member

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    Awesome, thanks for all your input so far guys. I'll report back later.
     

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