I've been considering the DIY options available, including the cost of materials and risk of voiding the Owon's Warranty, to reduce the GND noise on my scope. Yesterday I decided that the best option for me was to order a new PSU board and a capacitor to modify the Converter board from Owon. For those interested in the details, I've posted below the e-mails leading to this decision as well as the purchase transaction.
The agent responding to my e-mails is the same agent that previously indicated that Owon ---- "have not plan and exact date to make change for it now, because it is not quite abnormal" ---- referring to the GND noise. The good news is that he now confirms that changes in the PSU & Converter boards at least reduce the noise.
For those of you that have been holding out for a resolution of the GND noise issue before making a purchase decision, Owon's response seems to confirm previous reports of an early June resolution to the GND noise issue. If you are still cautious, check the forum in the coming weeks, I plan to post noise images before and after exchanging/upgrading the boards in my scope. Hopefully you can use these images to help you decide if the noise level is good enough for you.
As for those of us that already own a scope with the GND noise issue, Owon's response offers an alternative to a DIY solution for US $50 + money transfer fees. This is not as good as the free exchange that many of us believe Owon should have offered, but to me, it's not a totally unreasonable price to pay to improve the usability of your scope.
The bad news, at least for me, is that my bank charged me a $45 fee for the money transfer. Maybe doing the transfer via Western Union is less expensive if you can make it work. I have an account with them but I couldn't get their Web site to give me the option to transfer funds to a Bank Account in China. Maybe I didn't try hard enough or should have called them before giving up, but I just got impatient and used my bank's money transfer service instead.
I plan to open my scope later today to get acquainted with the procedures I'll need to perform when the Owon shipment arrives. While I'm at it I'm going to try ferrite cores in the cable between the PSU and the converter board, as well as from the converter board to other scope components. I'll be posting the results as soon as I get done.
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To: _____ (at Owon)
Subject: Re: GND Noise
Dear _____ or other Tech Support agent,
One of your customers reports that during a recent communication with Owon, one of your employees has indicated that the GND noise issue was resolved about three weeks ago. He also reported that Owon can supply the new boards (PSU & Adapter DC/DC) for about US $50. In an effort to resolve, or at least improve the GND noise on my unit, I would like to purchase these boards from you if they are indeed available. Please indicate the actual price and what needs to be done to complete this transaction.
Best regards,
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To: _____ (TomC)
Subject: GND Noise
Hi _____,
Sorry for my mistake information, after consulting about if from our engineer, I found this GND noise has reduced much by replacing new board. But please note that the noise can’t be solved 100%, but reduced.
Only two spares need to be replaced, one is Power Supply Board and the other is a Capacitance in convert board.
The price include shipping cost to USA is USD50 totally. Please pay to our bank account. (paypal or credit card are not acceptable, but western union is preferable)
If you agree, please tell me your below information:
Your address
Consignee
Telephone number
Our bank account is
BANK INFO
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||||||||||||||||||||| (I didn't post names or the bank information to protect privacy, but the bank information
||||||||||||||||||||| provided contained everything I needed to transfer funds from my bank account to their bank
||||||||||||||||||||| account)
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You could make payment firstly.
Have a nice day
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To: _____ (at Owon)
Subject: Re: GND Noise
Hi ______,
I just transferred USD50 to your bank account for the new boards. You should receive e-mail from my bank in my behalf shortly. My Address information is as follows:
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My telephone number is:
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To: _______ (TomC)
Subject: Re: GND Noise
Hi ______,
We got your payment, thank you.
We will make shipment soon.
Attached is to show the capacitance I mentioned need to be replaced.
Have a nice day