How hard would it be to replace these capacitors?

Discussion in 'Audio Hardware' started by jon9091, Oct 15, 2019.

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  1. jon9091

    jon9091 Master Of Reality Thread Starter

    Location:
    Midwest
    Yes...that’s it. That’s very interesting...thanks for finding that. So if the deck was failing to start the platter after pressing the power button, what would likely be the culprit?
     
  2. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    Since VPI "received the turntable assembled" in the video (probably outsourced to China, but then "made in America" when they inspect them and put on tonearms), the capacitors could be bottom-barrel counterfeit Chinese, especially if VPI seemed to know about the problem when contacted. Even a platter needing some lubrication might cause some issues though.

    The center capacitors are coded to be Panasonic S (A) series, part EEE1JA220UP (in 8mm diameter can, if 6.2mm tall), already a low-spec $0.17 85C 2000hr cap. Compared to an assembled-in-US product of mine using Panasonic S-series cap, the printing on yours looks a bit off, though:
    [​IMG]

    Might as well replace, if the solution was already hinted at. Besides $2 in upgrade EEE-HD1J220P capacitors, get a 12W Weller disposable soldering iron and some copper wick and 63/27 solder.
     
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  3. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    The answer should have been obvious - they are making a bi-polar capacitor out of two under-specified polarized electrolytic capacitors, in series with one reversed (back-to-back). The 40 cent solution.

    This of course is the bad way, you have one of the capacitors taking that current in the reverse direction. When the ESR rises, the caps can quickly get out of balance, have reverse voltage potential and dissipate power, or worse go kaboom. "Normally a capacitor cannot be reverse-biased for long, or large currents will flow and destroy the center layer of dielectric material via electrochemical reduction"; or from CDE: "While non-polar aluminum electrolytics are available for momentary-duty AC applications like motor starting and voltage-reversing applications, the high DF of aluminum electrolytic capacitors – from 2% to 150% – causes excess heating and short life in most AC applications."


    The through-holes on either side and silk screening seem to be for the correct non-polarized AC motor run capacitor component that they substituted out. This can be verified by seeing and measuring the traces connect to the "can cap" terminals on either side of the pair, and from there to the black and red leads. One could be installed from the top by just trimming the leads before soldering.

    [​IMG]

    Here's a likely candidate, $3 10uF AC 160V rated, with 27mm lead spacing (vs the 8mm cans): 106MMR250K

    [​IMG]
    More expensive, specifically motor-run capacitors, like Illinois-Capacitor-CDE 106MABA02KJS - have lifespans to 30000 hours instead of 2000.
     
    Last edited: Oct 16, 2019
    Phil Thien and jon9091 like this.
  4. jon9091

    jon9091 Master Of Reality Thread Starter

    Location:
    Midwest
    Thanks for your help everyone. VPI is sending out a whole new board as a replacement. In the mean time, I am still going to order the supplies and practice on the old board, to keep as a backup.

    Thank you again.
     
  5. jon9091

    jon9091 Master Of Reality Thread Starter

    Location:
    Midwest
    How is polarity indicated on that cap?
     
  6. misterdecibel

    misterdecibel Bulbous Also Tapered

    The orange one? It's non-polar.
     
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  7. Phil Thien

    Phil Thien Forum Resident

    Location:
    Milwaukee, WI
    Right. Make sure you apply additional solder, more solder is your friend here. Also, I use bamboo skewers to do my prying/lifting, I don't use the pointy end but rather sand a taper (think chisel) on the flat/dull end, works great. Gives me a little more leverage and saves burning my fingers, and won't do any damage if you slip off the part.

    BUT YOU HAVE to add more solder, then remove the excess solder with a vac or wick when you're done.
     
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  8. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    It is non-polarized, for AC currents. Install in either direction. The orange one is a metal film capacitor instead of electrolytic, which you'd find as a tube amplifier coupling capacitor.

    Two polarized capacitors, as used, can simulate this, but separate electrolytics are not ideal:
    [​IMG]

    You don't have to, but it makes it easier on lead-free devices when not using a proper lead-free-solder temperature iron.
     
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  9. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    I'm curious to hear what components were on the replacement board VPI sent out.

    Reviewing the thread, it seems pretty conclusive that they made an error in specifying motor run capacitor: 63V instead of 100V, 22uF instead of 10uF (perhaps thinking they were still in series if back-to-back), 2000hr 85 degree instead of 5000/105 like anyone but a penny-pincher would use (besides the polarized electrolytics not making a good home-brew non-polarized).
     
    patient_ot likes this.
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