Advice for Cleaning an Alps Power Switch from Onkyo TX-2500 MKII

Discussion in 'Solid State' started by ringading, Feb 11, 2018.

  1. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    I have a nice 2500 MKII that sizzles and flickers when I turn it on. From reading up on it here at AK it sounds like bad contact inside the switch. I tried cleaning it with DeOxit and contact cleaner and it worked briefly but is back to sizzling again.

    I am going to attempt to open the switch and clean the contacts as others have done according to some other threads here but was wondering if anyone has any advice. I have attempted to clean a couple of switches before but a few times they were nearly impossible to reassemble without having four hands and ninja skills.

    Short of cleaning it, is there a replacement? I didn't find any mention of one here or anywhere else but the direct question was never asked. It is an Alps L-403 Power Switch.

    Thanks all!
     

     

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  2. redk9258

    redk9258 Super Member

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    1,484
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    Illinois, close to St. Louis.
  3. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    Thanks redk - that is beyond my skillset - I wouldn't even know which relay to buy or how to wire it in.

    I took the switch apart and cleaned the contacts as well as I could with a bit if an emory board - put it back together and now it won't light up at all. Not sure what went wrong - there weren't any little parts that fell out and I could figure out how it worked from looking at it. Time to take it apart and see. The plastic tab that pushes the relay down was a bit melted from the arcing. Perhaps it isn't making enough contact with the metal plate that it slides across.
     
  4. Hak Foo

    Hak Foo Active Member

    Messages:
    294
    If there's another pair of contacts on the switch, you might try using those instead. It probably has far less degradation.
     
  5. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    There are two channels inside but only one of them has contacts. Looks like there should be another set of contacts but alas, no.

    At this point, replacement would be a better option if anyone can point me to a likely candidate but I can't find much online for an ALSP L-403 switch.
     
  6. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    Looking at the SM it is listed as NPS-111L12P.
     

     

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  7. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
  8. redk9258

    redk9258 Super Member

    Messages:
    1,484
    Location:
    Illinois, close to St. Louis.
    I doubt it would fit. Lets see some pictures of the switch.
     
  9. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    Here is the switch. I believe it is 5 amps (is that what TV-5 indicates?) with 20mm spacing and single pole.

    upload_2018-2-13_19-28-9.png

    upload_2018-2-13_19-28-57.png
     
  10. redk9258

    redk9258 Super Member

    Messages:
    1,484
    Location:
    Illinois, close to St. Louis.
    The mounting may work, but how about the button? You really should consider fixing the contacts again, if possible, and going the triac route. It's not hard. I've heard of some people taking contacts from a new switch and transplanting them in old ones. Hard to tell if any are close enough.
     
  11. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    The switch from digikey arrived today and works like a charm. Perfect fit for the mounting screws and for the power button as well - fits perfectly on the square shaft of the switch.

    I don't think the original was fixable as the metal blade was too bent down to make contact anymore and there is really no room in there to bend it back up.
     
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  12. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
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    Photo to show fit.

    upload_2018-2-16_22-25-17.png
     
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  13. redk9258

    redk9258 Super Member

    Messages:
    1,484
    Location:
    Illinois, close to St. Louis.
    Did you put that cap on the new one?
     
  14. ringading

    ringading Well-Known Member

    Messages:
    551
    Location:
    Auburn, WA
    If you are asking about the safety cap, I put a new one on.
     
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