Evh 5150 Iii No Sound

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Lareaubot, Apr 30, 2015.

  1. Lareaubot

    Lareaubot Member

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    Apr 30, 2015
    Hi everyone,

    I bought an EVH 5150 III a few years ago, and I haven't had any problems with it. At practice yesterday, I turned it on and all the lights came on. I took it off standby and there was no sound at all. No crackling. Nothing. I triple checked all volume levels, knobs, and standby switches to make sure it wasn't those.

    I plugged the guitar into a different amp with the same cable, and there was sound, so I know it isn't the guitar or the cable. I also switched out the speaker cable to rule that out. When I looked at the back of the amp, it didn't look like the tubes were glowing, and they weren't warm at all. The tubes are only a couple of weeks old (a matched set of JJs), but I've been using them just fine so far. Any ideas on what the problem could be? Thanks.

    -Jeff
     
  2. xtian

    xtian Member

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    Your amp has multiple fuses, including one specifically for the heater circuit, so it's possible for the front panel lights to work but not the heaters. You'll have to remove the chassis from the cabinet in order to check all the fuses.

    Usually, but not always, there's a reason for fuses blowing--bad power tubes, failed components, power surge, etc. Get it checked out by a tech.
     
  3. Lareaubot

    Lareaubot Member

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    Thanks xtian. I'll do that. Anyone know of any reliable amp techs near the Chicagoland western suburbs?
     
  4. Rajiv Thapa

    Rajiv Thapa Member

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    Hi there,
    I too f**d up my amp by connecting to a higher voltage PS. Actually I had in imported from USA to my place and was unaware of the voltage difference as it was my first purchase. In excitement I plugged in to my power source instantly and fried the fuse with 220v. Now, I have purchased a step-down transformer and replaced the fuse but again the problem is that the amp is completely dead.
    @Lareaubot could you find out what went wrong with your amp head when you get it fixed by the tech and share me some important details ? As there are no music instrument repair shops or any good electronic repair guys nearby my place. It would be really awesome if you could help me out. Thanks!!
     
  5. Kyle B

    Kyle B Supporting Member

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    That guys not gonna reply to you....his whole contribution to these boards is the two messages you see above from over 2 years ago.

    Also....what happened to him probably has NO relation to your issue even if it's the same amp.

    If you're gonna try to fix it yourself, you'll need meters and soldering equipment. Do you have those?
     
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  6. pdf64

    pdf64 Member

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    As @xtian notes above, the amp has internal fuses. Some of these are 'fast blow' (eg the HT fuse F1), whereas the back panel fuse, despite being a 'fast blow' type, will tend to blow slowly (due a series current surge limiting NTC resistor).
    ie there's a good chance F1 may have blown, as well as the back panel fuse.
    So in the first instance, perhaps get a competent person to check the fuses (and the NTC resistor TR1).
    http://schems.com/schematicheaven.net/manu/peavey/peavey_5150-II.pdf
     
    xtian likes this.
  7. Rajiv Thapa

    Rajiv Thapa Member

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    Yes, I do have meter and soldering equipment and some knowledge about electronics . Hehe
     
    Kyle B likes this.
  8. Rajiv Thapa

    Rajiv Thapa Member

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    Even I have a feeling that the fuse might be blown off, I really really hope it's only the fuse. Anyways I opened up the amp and checked for continuity on the fuses. Fuse 1 &2 doesn't have continuity but 4&5 has. Couldn't find the fuse 3 ....do you think it's only the fuse which is damaged ??
     
  9. Kyle B

    Kyle B Supporting Member

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    After replacing fuses and before powering up again, I'd think it wise to check all silicon especially the input bridge rectifiers. If your meter has a diode check function, this is easy to do.
     
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