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Come on Marshall, really?

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  • Come on Marshall, really?

    Valvestate VS-100 comes in for horrible loud noises. Soon as I powered it on and touched it, I experienced it. One thump on it's noggin verified a mechanical fault, which I found to be at the preamp tube. Pulled it and cleaned the socket, a little better maybe, but still unusable. Pull the board to get at the socket connections and what do I spy? Both ends of the spring clip retainer are contacting points on the board. The one at the upper right was sitting squarely on a solder pad, and the one at lower left had scraped through the insulation and was making contact with the trace. There was no evidence it was ever installed the opposite way, but even if it was it would have contacted the pad above the bottom hole. Also, notice a resistor leg that was just barely soldered in.

    How could Marshall have been so foolish or careless? Are all of the run of this model like this, just waiting to short themselves out? It really does look like this is original, and not someone else's blunder after the fact.

    Click image for larger version

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    It's weird, because it WAS working fine.....

  • #2
    Nice. "Here, let's just attach the tube retainer to the PCB!"

    Also, I see you have cold solder joint on pin 7. Reflow them all.
    --
    I build and repair guitar amps
    http://amps.monkeymatic.com

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    • #3
      I don't have any schematics on the Valvestate amps, but find it odd that the spring retainer would be sitting at Pin 9 heater potential, with the upper contact appearing to be connected thru a resistor to the cathode at pin 8. No idea what that component is where the lower spring contact pint is going. What was the product design team thinking here??? I gather the heater is 12.6V, as I see both pins 4 & 5 leaving the view towards the left. I've never seen this one before!
      Logic is an organized way of going wrong with confidence

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      • #4
        With the large pad, one might assume pin 9 is heater CT ground/plane. but still, the springs being allowed to touch any of it seems a bit dunder-headed.
        If it still won't get loud enough, it's probably broken. - Steve Conner
        If the thing works, stop fixing it. - Enzo
        We need more chaos in music, in art... I'm here to make it. - Justin Thomas
        MANY things in human experience can be easily differentiated, yet *impossible* to express as a measurement. - Juan Fahey

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        • #5
          Yup.

          I have seen that one before.

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          • #6
            It also looks like very little solder on the joint left of the left side of the retaining clip.
            "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

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            • #7
              Yes, I bend the clip so it doesn't touch anything.

              Got a JVM mega super duper head in this week.

              Can't believe they get a couple grand plus for these things new.

              Nice technical design and features, but not exactly executed too well.

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              • #8
                yeah, this is the before pic. I bent the clip ends away from harm and soldered the points in question.
                It's weird, because it WAS working fine.....

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                • #9
                  Geez! Marshall quality is pretty low and for the cost? Ha, I'll take a Crate.....

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                  • #10
                    It's not just Marshall.

                    Crappy soldering to me is typical of any amp that I take in.

                    And that tube retainer thing has been going on since they designed the amp.

                    To me it comes down to QC.

                    Who the heck is in charge?

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                    • #11
                      Originally posted by Jazz P Bass View Post
                      It's not just Marshall.

                      Crappy soldering to me is typical of any amp that I take in.

                      And that tube retainer thing has been going on since they designed the amp.

                      To me it comes down to QC.

                      Who the heck is in charge?
                      Obviously not service-oriented folk who've done repair work. So much of the mechanical problems we have to cure goes right back to the engineering group who's leaders also don't see what we see every day repairing their design flaws. As Jazz P Bass said, crappy soldering. I probably spend 90 % of my time repairing solder fractures. I haven't seen the other side of Randall's Valvestate 100 amp to fully appreciate this dodgy mess Marshall unleashed on us.

                      Also, is there a picture missing in Post # 8?
                      Logic is an organized way of going wrong with confidence

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                      • #12
                        "Also, is there a picture missing in Post # 8?"

                        No. I was referring to the picture in post #1 before the repair.
                        It's weird, because it WAS working fine.....

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                        • #13
                          Originally posted by nevetslab View Post
                          Obviously not service-oriented folk who've done repair work. So much of the mechanical problems we have to cure goes right back to the engineering group who's leaders also don't see what we see every day repairing their design flaws.

                          ...crappy soldering. I probably spend 90 % of my time repairing solder fractures.
                          Mechanical flaws go unnoticed because designers don't repair the stuff they design.
                          Slipshod assembly goes unnoticed because assemblers don't use the stuff they assemble.

                          It could be worse.

                          Generally, guys (and it is still mostly guys) who design cars and guitar amps and power tools do drive and play guitar and build stuff.
                          But how many guys who design stoves and dishwashers and washing machines actually cook and wash dishes and do laundry?

                          -rb
                          Last edited by rjb; 11-29-2017, 09:26 PM.
                          DON'T FEED THE TROLLS!

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