OWON 100MHz SDS7102V Repair - Page 1
Forum section: electronics / repair

author: Zero999
author_rank: Super Contributor
timestamp: March 29, 2016, 10:08:28 pm
content: One the channel 1 input is damaged. A colleague of mine connected one of the probes to a current transformer and injected a high voltage into it. The probe was melted and charged but was easily replaced.Now there's a permanent 280mV offset, when the probe is connected to a low impedance source and DC coupled, which doesn't go away after running the auto-calibrate routine. It seems like the offset is caused by 280nA leakage current. When the input isn't connected to anything, the offset disappears. When I connect my multimeter to the input, it measures 280mV on the voltage setting and 280nA on the current setting.Has anyone else had a similar problem?The input is screened with a metal cage, which will be difficult to unsolder so I haven't done anything, except remove the case.

author: tautech
author_rank: Super Contributor
timestamp: March 29, 2016, 10:45:55 pm
content: Shame, any lessons learn't? (don't lend your scope)Don't know if rf-loop can help you, he's an Owon dealer.

author: Zero999
author_rank: Super Contributor
timestamp: March 30, 2016, 07:48:53 am
content: Quote from: tautech on March 29, 2016, 10:45:55 pmThe silly sod didn't apply Ohm's law properly. The burden resistor he used didn't have a high enough power rating, smoked, failing open circuit, allowing the poor probe and oscilloscope to take the hit.Quote from: GEuser on March 30, 2016, 04:07:04 amThanks. I'm not going to do much with it at the moment because the company is going to organise replacement/repair.If get a new one, I can then take a closer look at it.

author: Zero999
author_rank: Super Contributor
timestamp: March 30, 2016, 10:29:32 pm
content: I've messaged the ebay seller who sold it to me about this. He said he might be able to get it repaired, if I send him the serial number and a photograph, along with a description of the problem.

author: Shock
author_rank: Super Contributor
timestamp: March 31, 2016, 09:16:49 am
content: Quote from: Hero999 on March 30, 2016, 10:29:32 pmBe careful with this as there is nothing to stop him from saying thanks very much and selling it off.

author: Zero999
author_rank: Super Contributor
timestamp: March 31, 2016, 10:13:17 pm
content: That's a good point but even if they can't fix it, I'll still want it back as it's still of some use.I think I'll get a new one ordered on the company, as it'll be the easiest solution.

author: Shock
author_rank: Super Contributor
timestamp: April 01, 2016, 12:44:20 am
content: Quote from: Hero999 on March 31, 2016, 10:13:17 pmI've been caught in a similar situation over a smaller amount before, was a huge supposedly reputable seller as well (UK based I think).What happens is communication stops dead as soon as they have your item or even worse they say it's ready after a couple of weeks and to send some money. As a rule doing anything outside of Ebays or Paypals protection generally ends in tears.A better solution is contact a legitimate distributor or the manufacturer and go through them directly.

author: Zero999
author_rank: Super Contributor
timestamp: April 01, 2016, 07:34:19 pm
content: Unfortunately I've messaged the seller, who doesn't seem to be very knowledgable. Here's a copy of our correspondence:Quote from: meQuote from: sellerQuote from: meQuote from: sellerQuote from: meI felt like banging my head on the computer keyboard, after sending this!