DP832 Overvoltage - Replacement works great, happy now!  - Page 1
Forum section: electronics / testgear

author: tech5940
author_rank: Unknown
timestamp: July 02, 2015, 11:30:59 pm
content: Hello all, just received my Rigol DP832. It appears there is a serious malfunction with Ch1. Hooked it direct to my multimeter with banana cables to play around with the interface and get used to it. Turned Ch1 on, selected a low voltage around 9 volts or so everything was fine. Upped the voltage past 12v and all of a sudden its displaying over voltage protection but I don't even have OVP turned on. It had jumped to 37v with a set voltage of only around 12 (seemed as I approached 12.5v, it would all of a sudden jump to 37v) I wondered if maybe it was because no load on the device, so I hooked up a battery charger that takes around 12-15v in. Hooked that up and at 12v it was fine, started to up the voltage a bit, as soon as it got above 12 BOOM it blew up the charger. The multimeter was still connected and yes it had jumped to 37v.As I was typing this I had been playing around with voltage starting at 12v and increasing in 00.10v steps and repeatedly as it got near 12.5 it would make the jump to 37v. I'd turn it down to 12v and restart it try the same thing and it would repeat. Then without me touching anything it started fluctuating between 12 and 14v (I had it set for 12v) then it stabilized back at 12v I tried the test again and this time it was working fine,went past 12v and kept the set voltage all that way into the 20v's. I tried setting the voltage to 30v, no problem it did. Now while still typing this its back to its tricks. Go past 12.43v and it goes into over-voltage and turns the output off.I will have to wait until Monday to get any support on the phone, holiday tomorrow for the US and everyone is closed for the day. Frustrating is all.I also notice the output takes forever with no load to drop down to 0v when turned off. If its set to 12v, takes 12 seconds when I turn the Ch1 off to reach close to 0v. I try the same thing with Ch2 and its almost instant.Anyway just sharing the story, anyone else had this happen to them?Oh and no I'm not mad about the battery charger, I mean it was a bit dumb of me to try that when I was suspecting a problem on the output..Oh I know people will likely ask this:The Cal certificate is dated May 2015. Firmware says Digital Version 00.01.13***UPDATE :I'm now noticing Ch2 which I thought was working fine is showing a constant 0.15A being drawn with NOTHING connected to the outputs. I'm pretty sure CH3 is good though!

author: dadler
author_rank: Unknown
timestamp: July 02, 2015, 11:49:25 pm
content: It's broken. Return for replacement.Rigol is "affordable" for a reasonbut even the best devices can be defective.I wonder how this slipped through QA?

author: tech5940
author_rank: Unknown
timestamp: July 02, 2015, 11:54:57 pm
content: Quote from: dadler on July 02, 2015, 11:49:25 pmOh yeah I'm sure it will be no problem to get a replacement, but yes I do wonder how it passed calibration like this.. I mean its not like it was just out of spec by a small margin!

author: Howardlong
author_rank: Super Contributor
timestamp: July 02, 2015, 11:58:15 pm
content: I managed to blow Ch1 here with your symptomshttps://www.eevblog.com/forum/testgear/rigol-dp832-smoked-channel-1/msg619848/#msg619848

author: tech5940
author_rank: Unknown
timestamp: July 03, 2015, 12:16:50 am
content: Quote from: Howardlong on July 02, 2015, 11:58:15 pmOh that's too bad, glad you got it fixed though.Mine was acting funny long before I plugged anything into it that would put voltage back into it though. I think about the only thing I could have done is had the banana plugs short while plugging them in. I'd assume this power supply should be able to handle a short though if that were to happen.I'm now noticing Ch2 which I thought was working fine is showing a constant 0.15A being drawn with NOTHING connected to the outputs. I'm pretty sure CH3 is good though!

author: f1rmb
author_rank: Regular Contributor
timestamp: July 03, 2015, 04:47:57 am
content: The top board is smoked, just like what I've experienced (see my post about that) . CH3 is on the bottom board. Rigol EU sent me a new top board, new revision, and since then it works as expected.Cheers.---Daniel

author: tech5940
author_rank: Unknown
timestamp: July 03, 2015, 05:38:03 am
content: Quote from: f1rmb on July 03, 2015, 04:47:57 amOk thanks, I had a quick look at the DP832 threads, I'll read the rest tomorrow night if I have time. Was yours faulty out of the box or did it happen over time? (Sorry I found some of your posts, but didn't see what started them off)

author: f1rmb
author_rank: Regular Contributor
timestamp: July 03, 2015, 06:18:00 am
content: Hi,No, the PSU as working for 2 or 3 weeks, IIRC, then I got OV alarms and similar problems as yours (with blown fuses and so on).Cheers.---Daniel

author: tech5940
author_rank: Unknown
timestamp: July 07, 2015, 11:22:51 pm
content: My replacement power supply arrived today, after an initial panic when the M5 button didn't work, after several firm button presses its now working. The output voltage/current seems to be stable and all in order as well. Very happy with this one.