Noise from Owon PDS5022S Oscilloscope

Discussion in 'General Electronics Chat' started by Redstone2, Jan 9, 2011.

  1. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    Hello,

    My wife got me an Owon PDS5022S oscilloscope for a combo Christmas and B-day present. After bread-boarding an astable 555, I had a blast running the numbers and checking with the oscilloscope. Got the Owon out to the workshop this weekend and noticed something not evident when using it on the coffee table and family around, it buzzes. It's not loud but with no music or anything going on, it is noticeable. The buzz sounds like when you pinch off a balloon tightly but the air leaks with a high freq sound. This noise is a steady pitch.

    Is this normal? Anyone own one to comment? Thanks for any feed back.

    I've been lurking and learning.... thanks for everyone's time! It's a great board.

    Regards,
    Tom
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Could just be the SMPS. Any loose laminations in an inductor will cause a buzz.
     
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  3. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    I'd get it replaced under warranty.

    New equipment shouldn't make noise unless it is an alert of some sort.
     
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  4. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    Thanks for the replies. While setting here typing, with the laptop fan running, and the oscilloscope about 12" from the keyboard I can hear the noise. Not as loud as the fan but you can hear the buzz.
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    I own one, and it does not make any noise that you can hear from 6 inches away.

    and NO squeeling noise.

    I would suspect a bad coil or driver in the SMPS..

    Maybe even a bad line filter CAP.

    Point is, IT is not supposed to be there, and get it replaced before is melts, or the warranty expires.

    P.S. Melting is not good. ;)
     
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  6. tom66

    Senior Member

    May 9, 2009
    2,613
    214
    Is there any abnormal noise on the trace or the test probe output?
     
  7. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0

    Retched,
    Thanks for your post. A search showed that you own one and I was hoping you would see my post.
    The Owon was on sell for $252 USD. I'll see how good the advertised three year warranty is. Only had it for two weeks now.
    Tom

    Hello Tom,
    Both traces look good, some noise, nothing excessive. But this is my first scope, never used one prior to this. The 1 KHz scope output looks clean. Attached is the output from an astable 555.
    Tom
     
  8. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    Attached is scope output 1 KHz output prior to calibration. Making one with calibration now.
    Thanks for the help.
    Tom
     
  9. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    This is after calibration
     
  10. tom66

    Senior Member

    May 9, 2009
    2,613
    214
    It's probably okay then, but I wouldn't rely on it. Perhaps contact the seller, or better yet, the manufacturer.
     
  11. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    I would not delay. Get it replaced before you get too attached, and "cant live without it" while it is in transit.

    Contact the seller or Owon and see if they will send you the new one and pick up the bad one at the same time.

    That way you need not live without it during transit.

    When emailing the company, link to this thread. That way they can see that it is being handled publicly. They will likely do the "right" thing quicker.
     
  12. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    Just got a reply from the vender, http://www.tmatlantic.com/ , they are sending a prepaid return label. I call that good customer service.

    I'm not affliated with tm atlantic in any way other than a customer. I think the sell price, 10% off and free shipping for orders over $250.00, is still good. When the order was shipped, they sent a tracking number... which is something I love.

    Tom
     
  13. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Are they sending a new unit along with the return shipping label? Or do you have to wait until they receive your unit back before they ship a new one?
     
  14. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    They did not go that far, just pre-paid shipping both ways.
     
  15. orbiter

    Active Member

    Jun 17, 2010
    58
    3
    JFYI.. I had an OWON PDS5022S scope not too long ago and mine didn't make any noise at all. Your doing the right thing in sending it back.
     
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  16. Redstone2

    Thread Starter Member

    Oct 21, 2010
    20
    0
    Follow-up.

    I received the replacement unit on Jan 20th and wanted to check it out before posting. The noise is gone (unless you place your ear at the vent slots) and all functions work within specifications (as far my limited experience can tell).

    Vendor stood behind the product, shipping a new unit after they received and checked out the defective unit.

    Since this public forum could have been used against the vendor if things had happened differently, I feel it appropriate is say that I am highly pleased with my purchase from http://www.tmatlantic.com/offers

    The Owon PDS5022S is still on sale for $252.00 with free shipping until Jan. 31.


    Hope that is not out of line.

    Thanks for all the help!

    Cordially,
    Tom
     
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