Author Topic: Rigol DP832 Random Reboots  (Read 3921 times)

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Offline cidcorp

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Rigol DP832 Random Reboots
« on: February 11, 2014, 08:28:03 AM »

I sat back and watched the issues relating to the 'lack' of heat dissipation on one of the regulators used in the Rigol DP832 and
waited for it to get sorted out before I committed to purchasing a unit.  I ordered at the beginning of the new year and to the best
of my knowledge (haven't opened the unit) it's the latest board revision with the larger silver heat sink (I can see it through the grill).

My problem is in the past couple days I started using it longer periods of time and I've noticed a serious issue.  If left idle (I've only
noticed this with the channels OFF) eventually it reboots.  I saw it through the corner of my eye a couple days ago and I noticed it 10 minutes
ago when I was actually looking straight at it.  It was only on for about 20 minutes. Temperature listed on the unit (in the Utility Test/Cal area) hovers
around 34.42.

I'm glad I noticed the reboot because I was using it on a 3.3v 5" LCD display/controller board, and silly me I didn't set the 'Power On' option to LAST setup and it
was instead set to DEFAULT (CH3 5v)...things would have ended badly for the display and board. if I enabled the output without noticing the change.

I just wanted to know if anyone else has noticed this happening?  I'm on firmware 1.06, and yes I'll consider the later firmware if it seems like it's a fix.  Has anyone else
had issues with random reboots?  The dead giveaway is the sound of the FAN switching to FULL while it is rebooting...

I may have to check inside to see how the 'fix' was implemented on my unit.  For now I'm letting it idle and checking the temperature for when it reboots.

Chris
 

Offline taemun

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Re: Rigol DP832 Random Reboots
« Reply #1 on: February 11, 2014, 01:36:30 PM »
Quote
I'm glad I noticed the reboot because I was using it on a 3.3v 5" LCD display/controller board, and silly me I didn't set the 'Power On' option to LAST setup and itwas instead set to DEFAULT (CH3 5v)...things would have ended badly for the display and board. if I enabled the output without noticing the change.

Ouch. Are you able to set the power-on defaults to 0V so that this doesn't happen in future?
 

Offline cidcorp

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Re: Rigol DP832 Random Reboots
« Reply #2 on: February 11, 2014, 03:32:02 PM »

Well the good thing is that all channels are OFF by default when the power supply cycles.  I have now set it to LAST in the Power On setting, so I
at least feel a little better walking away from the bench for a while.  I've tested it and the settings are retained after it cycles.

After watching the temperature on the supply for close to an hour and half of use, I can't say that it's probably not the temperature of the device.  I do admit that it starts to
climb very very slowly over time...starting at 34 and climbing over a hour and a half to 35.25 and I suspect it will continue, but this doesn't alarm me because
I was using the supply during this time and I'm surprised that's all it climbed to.

I'm going to assume no one else has run into this problem... the few I've talked to are at the latest firmware and haven't seen this issue.  I maybe just my unit
as well.  I'll start documenting the reboots to keep a record.

Chris
 

Offline H.O

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Re: Rigol DP832 Random Reboots
« Reply #3 on: February 11, 2014, 06:03:18 PM »
Hi,
I've got mine for ~6months, it's the old board with the small heatsink. I don't use it on a daily basis, sometimes not even weakly but I'm yet to see it reboot. I'm on 230VAC nominal, haven't measured actual.

Have contacted Rigol - twice - about getting the board replaced without even getting a response. I'm not TOO bothered though, I'll probabaly live with it, and fix it myself when the times comes.

But, your unit is with the new heatsink which is supposed to fix the issue. I can't believe it's STILL the same regulator overheating....
 

Offline uski

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Re: Rigol DP832 Random Reboots
« Reply #4 on: February 12, 2014, 02:02:08 AM »
Hi,

I've heard about people replacing that linear regulator with a small switch-mode power supply module out of eBay, like this one :

http://www.ebay.com/itm/DC-DC-Buck-Converter-Step-Down-Module-LM2596-Power-Supply-Output-1-23V-30V-/181227591312?pt=LH_DefaultDomain_0&hash=item2a32019690
DC-DC Buck Converter Step Down Module LM2596 Power Supply Output 1.23V-30V

$0.99 each, shipped.

(don't forget to adjust the output voltage before connecting it to the circuit)

uski
 

Offline Electro Fan

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Re: Rigol DP832 Random Reboots
« Reply #5 on: February 12, 2014, 07:12:54 AM »
Hi,
I've got mine for ~6months, it's the old board with the small heatsink. I don't use it on a daily basis, sometimes not even weakly but I'm yet to see it reboot. I'm on 230VAC nominal, haven't measured actual.

Have contacted Rigol - twice - about getting the board replaced without even getting a response. I'm not TOO bothered though, I'll probabaly live with it, and fix it myself when the times comes.

But, your unit is with the new heatsink which is supposed to fix the issue. I can't believe it's STILL the same regulator overheating....

Maybe there is a possibility that the reboots other people are experiencing are caused by something other than the regulator and/or the overheating?
 

Offline cidcorp

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Re: Rigol DP832 Random Reboots
« Reply #6 on: February 12, 2014, 07:33:30 AM »

I'm not going to tag it as a regulator problem.   I can't trust the temperature shown on the cal screen.  Now the power supply
is playing nice, and I haven't caught it rebooting since I posted. If it starts doing it again, I'll be directly checking the temperature
of that regulator with a probe.  And yes, I should upgrade the firmware to eliminate that as the issue as well.

It could be anything, and could be isolated to mine... so for now I'm happy that no one else out there has the same problem.

Chris
 

Offline skrap

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Re: Rigol DP832 Random Reboots
« Reply #7 on: November 19, 2016, 08:53:26 PM »
Did you figure out what the problem was? I have a brand new unit that does the same thing but even more often. Sometimes it will just be a short glitch on the screen and then it will hang until manual power cycling.
 

Offline Macbeth

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Re: Rigol DP832 Random Reboots
« Reply #8 on: November 20, 2016, 09:10:19 AM »
Did you figure out what the problem was? I have a brand new unit that does the same thing but even more often. Sometimes it will just be a short glitch on the screen and then it will hang until manual power cycling.

I just had mine reboot even though it had not been used in a month and was just switched on for 10 minutes. I have never had it hang, but it certainly has rebooted a few times over the past few years for absolutely no reason.

In actual use it also has issues with powering certain boost converters like XL6009. It just goes loco.

It can not be trusted as unaided test equipment. I now use my old school HP 6632B for anything like that - 20V and 5A - it's a great boat anchor (or monitor plinth in my case)
 

Offline skrap

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Re: Rigol DP832 Random Reboots
« Reply #9 on: November 20, 2016, 02:28:15 PM »
Is that one with the updated PCB with a larger heatsink and mosfet or the older one with the heat problem?

For me it seems like I was just unlucky, now it reboots or hangs within 1 min of turning on so something is really wrong with this one. |O Would have been interesting to take it apart to figure out what's happening but it's probably not worth to gamble the warranty. I have an HP as well that I enjoy but I kind of like this DP832 unit even though all the quirks.
 

Online _Wim_

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Re: Rigol DP832 Random Reboots
« Reply #10 on: November 20, 2016, 06:21:56 PM »
I have 2 DP832 units that I use quite regularly (bought end 2014) So far I have never seen the reboot issue, but I haven’t watched for it specifically. They have never hang so far, that I am sure.
 

Offline RoGeorge

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Re: Rigol DP832 Random Reboots
« Reply #11 on: November 20, 2016, 09:02:35 PM »
The only reset I saw on my DP832 was last month. Ch1 and Ch2 were in parallel (through a double diode, in order to charge a car battery). Both channels were set to 3A/18V each, while constantly logging the outputs values using SCPI commands over LAN (once a minute).

I was just increased the current from 0.3 to 3A (manually, on each CH1 and CH2 so the total generated power was under 85W), then after about 5 minutes at 80W, it reset under my eyes. After the reset, all the channels were in stop mode.

I couldn't reproduce the reset, so I let it charging the car battery over night at 2x3A and SCPI logging over LAN, and it didn't reset any more. Also, no other reset that I know of since I bought the DP832 about 2 years or so, but it was used only rarely, and usually for very small loads (1-10W for all 3 channels added).

I suspect the reset has something to do with the fact that SCPI commands were sent (for data logging) while manually changing the current from 0.3 to 3A. I am saying this because the last DP832 logged (in the PC) was at 0.3A, but the reset happened a few minutes later after the current was increased from 0.3 to 3A, so I should have seen a few records in the log at 3A, but there are no records logged at 3A. These are the last 3 records in the PC log:

Code: [Select]
YYYY-MM-DD,HH:MM:SS,CH1(V),CH1(A),CH1(W),CH2(V),CH2(A),CH2(W),CH3(V),CH3(A),CH3(W)
...
2016-10-30,01:19:25,12.5654,0.3993,5.017,12.5716,0.3947,4.962,0.0000,0.0000,0.000
2016-10-30,01:20:25,12.5648,0.3993,5.017,12.5711,0.3947,4.962,0.0000,0.0000,0.000
2016-10-30,01:21:25,12.5644,0.3993,5.017,12.5706,0.3947,4.962,0.0000,0.0000,0.000

During all this time, a DMM was also logging the battery voltage and current. The multimeter logged a few minutes between the manual current increase and the reset, but these minutes are missing from the DP832 log, so I guess it was like this:
- DP832 generating under 10W while logging the data into PC
- manually change the current (from the DP832 front panel) for CH1 and CH2 from 0.3A to 3A
- the software hang, because I have no 3A records
- after a couple of minutes, the DP832 reset. During these minutes, the DP832 was generating less then 100W, and the current was stable, and at the expected (as shown in the DMM logs).

I don't know where to look for the firmware version details. The 'Utility' -> 'System' shows 'Digital version: 00.01.11'. The hardware is the version with a big radiator (the radiator can be seen through the air holes).

This is what the DMM was logging. The blue cross is marking the DP832 reset. After the reset, all the DP832 were off. The charts shows the same values before and after reset because I manually turned on the DP832 channels after the reset. The various steps in the charts are because the current or voltage were manually adjusted in the DP832 a few times during the whole battery charging.

Offline Pinkus

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Re: Rigol DP832 Random Reboots
« Reply #12 on: November 20, 2016, 09:49:38 PM »
Hi,

I've heard about people replacing that linear regulator with a small switch-mode power supply module out of eBay, like this one :

http://www.ebay.com/itm/DC-DC-Buck-Converter-Step-Down-Module-LM2596-Power-Supply-Output-1-23V-30V-/181227591312?pt=LH_DefaultDomain_0&hash=item2a32019690
DC-DC Buck Converter Step Down Module LM2596 Power Supply Output 1.23V-30V

$0.99 each, shipped.

(don't forget to adjust the output voltage before connecting it to the circuit)

uski
Seriously? Using a crappy Chinese $1 (including shipping) stepdown module (=made of 100% fake/dubious quality products*) for an expensive lab equipment  :scared:? If this fails (and chances are high it will at some day), it will fry your DP832.

* try to calculate. subtract shipping, packing, margin etc. you will find, they are producing this for a BOM of maybe $0.3. Now try to find LM2596, 2x 36V caps, 3A inductivity, 3A schottky, precision trimmer for $0.3 .... no way, even if you would go an buy 100K or 1M of them.


 

Offline sdouble

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Re: Rigol DP832 Random Reboots
« Reply #13 on: November 21, 2016, 07:08:54 AM »
I suffer from that issue too.
I reported that here :
http://www.eevblog.com/forum/blog/eevblog-512-rigol-dp832-bad-design-investigation/msg1071713/#msg1071713
I use them with the 230V 50 Hz main. Are you also using it in europe ?
 

Offline skrap

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Re: Rigol DP832 Random Reboots
« Reply #14 on: November 21, 2016, 03:50:07 PM »
Europe here, 230 VAC / 50Hz with what seems to be the latest hardware revision. At least the large heatsink but I can't confirm the new mosfets or not, firmware is the latest version and calibration was done in June. The supply works really well and is within spec. when it doesn't hang or reboot but this typically happens within a minute now no matter if the outputs are on or off. Since it's very repeatable I guess something on the digital side is overheating for some reason.
 

Offline skrap

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Re: Rigol DP832 Random Reboots
« Reply #15 on: November 22, 2016, 10:41:03 AM »
Got a new one and this one is flawless, at least so far ;-) All the design quirks are still there of course but I can't really say I mind them much at all actually. Latest hw and software revisions really makes this a nice powersupply indeed.

At least until the dreaded reboot rears its ugly head once again... but hopefully no more.
 

Offline sdouble

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Re: Rigol DP832 Random Reboots
« Reply #16 on: November 23, 2016, 06:34:16 AM »
Europe here, 230 VAC / 50Hz with what seems to be the latest hardware revision. At least the large heatsink but I can't confirm the new mosfets or not, firmware is the latest version and calibration was done in June. The supply works really well and is within spec. when it doesn't hang or reboot but this typically happens within a minute now no matter if the outputs are on or off. Since it's very repeatable I guess something on the digital side is overheating for some reason.
what is the latest revision ?
 

Offline skrap

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Re: Rigol DP832 Random Reboots
« Reply #17 on: November 23, 2016, 02:01:20 PM »
It's DP8C 2.20 I beleive, I'm not sure about the number but it's the one with new heatsink and larger mosfet.
« Last Edit: November 23, 2016, 02:11:31 PM by skrap »
 

Offline envisionelec

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Re: Rigol DP832 Random Reboots
« Reply #18 on: June 02, 2017, 01:10:09 AM »
I just got a message from a friend who bought my 2016 (post regulator update) DP832 a couple months ago. He says it get stuck in a reboot loop especially when cold. It warms up then stops resetting and begins to work. Anyone see this?
 

Offline RoGeorge

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Re: Rigol DP832 Random Reboots
« Reply #19 on: June 02, 2017, 06:23:07 PM »
If any electronics are doing strange things only when cold, then check for bad capacitors with high ESR.


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