Author Topic: EEVblog #512 - Rigol DP832 Bad Design Investigation  (Read 254511 times)

0 Members and 1 Guest are viewing this topic.

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #550 on: February 19, 2014, 06:08:33 pm »
I sent a polite email to "info@rigol.com" last night stating the timeline of my issue and asking for either a fix or at least information on when the fix would be offered.  I received an email back a few hours ago from a gentleman at Rigol who sent an RMA form and a pre-paid return shipping tag.  He mentioned they had been kept waiting for the repair parts, and that it was taking time to work through the backlog of units for repair. 

At least it appears they are now performing the fixes - hopefully the turnaround time won't be too bad.  I have other supplies I can use so I won't miss this one for a couple of weeks, but I hope it doesn't end up taking a couple months.  I don't think it will - they told me they should be able to turn it quick.

So for anyone still waiting, I guess you could either wait for contact knowing they are doing fixes, or you could email info@rigol.com and ask them to ensure you are on the list, at least.

Hope it helps.

Any update on this?  I wonder if you sent your DP832 back for the board replacement?  If so, have you got it back yet?  How has the correspondence been from Rigol NA about the process?

Thanks!

Funny you mention that - I actually haven't sent it back yet, but I plan to this week.  Literally the day I got the shipping tag, a little emergency project fell into my lap using some white COB LED's that take over 30 volts.  I needed my DP832 to run these reliably so I figured I will send it when I am done.  I wrapped it up over the weekend and should get the unit out tomorrow.


I can update that I sent my DP832 for heatsink fix (Rigol RMA with shipping label) and the turn around was 4wks (plus additional 2wks for shipping there and back); it took longer than I expected.

The unit has the new (tall silver) heatsink in it, as expected.  It was also updated with firmwares (digital) 00.01.09, (analog) 01.02.00 and (boot) 01.06.

I have not tested it much since I got it back, but I note that it was (re)calibrated in Feb 2014.  Also, on the Test/Cal screen it shows the temperature is 11.82 (degC) --- it is not under load, but still that seems very low!
« Last Edit: February 19, 2014, 06:10:25 pm by Sparky »
 

Offline Galaxyrise

  • Frequent Contributor
  • **
  • Posts: 526
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #551 on: February 19, 2014, 06:25:24 pm »
I have not tested it much since I got it back, but I note that it was (re)calibrated in Feb 2014.  Also, on the Test/Cal screen it shows the temperature is 11.82 (degC) --- it is not under load, but still that seems very low!
Temperatures on cal screens are sometimes relative to the temperature the unit was calibrated at.  If that's the case, 11.82 seems high but not inconceivable (absent more data)... what is your ambient temperature?
I am but an egg
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #552 on: February 19, 2014, 06:36:03 pm »
I have not tested it much since I got it back, but I note that it was (re)calibrated in Feb 2014.  Also, on the Test/Cal screen it shows the temperature is 11.82 (degC) --- it is not under load, but still that seems very low!
Temperatures on cal screens are sometimes relative to the temperature the unit was calibrated at.  If that's the case, 11.82 seems high but not inconceivable (absent more data)... what is your ambient temperature?

Ambient temperature is 23.6 degC, while the temperature reading shown on the DP832 screen is now 12.11 degC. 

The temperature of the tall silver heatsink on the LM317 is now 54.7 degC.  I dunno where the sensor is that's giving 12.11 degC, but it just seems too low...
 

Offline mcinque

  • Supporter
  • ****
  • Posts: 1032
  • Country: it
  • I know one thing: that I know nothing
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #553 on: February 19, 2014, 06:49:33 pm »
the turn around was 4wks (plus additional 2wks for shipping there and back)

SIX weeks?! more than a month?! :wtf: :rant: holy s**t...
I'm basically still a rookie and because of this, even with the best intentions, I often say bullshits
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #554 on: February 20, 2014, 03:06:23 am »
I have not tested it much since I got it back, but I note that it was (re)calibrated in Feb 2014.  Also, on the Test/Cal screen it shows the temperature is 11.82 (degC) --- it is not under load, but still that seems very low!
Temperatures on cal screens are sometimes relative to the temperature the unit was calibrated at.  If that's the case, 11.82 seems high but not inconceivable (absent more data)... what is your ambient temperature?

Ambient temperature is 23.6 degC, while the temperature reading shown on the DP832 screen is now 12.11 degC. 

The temperature of the tall silver heatsink on the LM317 is now 54.7 degC.  I dunno where the sensor is that's giving 12.11 degC, but it just seems too low...

And now it is confirmed as a bug in 01.09.


SIX weeks?! more than a month?! :wtf: :rant: holy s**t...

Yep!  You're not wrong!  Hopefully they'll speed it up, but people should be prepared to do without for a while.  For some, it might not even be worth the hassle...
 

Offline Marc M.

  • Regular Contributor
  • *
  • Posts: 132
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #555 on: February 26, 2014, 09:40:40 am »
I used a DSN2596 which is an assembled PCB module that was very inexpensive at $1.44 with free shipping.
Thanks Ted for the heads up on this inexpensive solution :-+.  I've had my RMA info. for my DP832 for a while now.  I was holding off on sending it in because they install .09 firmware which can't be downgraded.  Also, I didn't want to be without my PS for 6 weeks |O.  So I threw caution to the wind, tore off the warranty sticker and installed one of these modules.  The module has 2 isolated holes in the board for mounting.  On the Rigol board there's a board mounting screw in the area of the regulator so I mounted the replacement module in that position using a longer screw and few nylon washers.  It worked out very nicely.

...I pulled out the potentiometer and replaced it with two SMT resistors...
The pot on the board was wired as a variable resistor i.e. 2 legs were shorted together.  I set it for 5v, pulled out the pot and measured it right at 1k.  Conveniently, the manufacturer placed smd pads underneath the pot so it was simple to set it to a fixed voltage.  I soldered in a 1k smd resistor which yielded 4.96 vdc out.  Meh, close enough.  I put the power supply back together, fired it up and discovered it was in about a 5 second reset loop  :palm:.  I didn't want to mess around with swapping fixed resistors so I just re-installed the original pot.  I set it for a touch over 5 volts and put it back together.  It was good for about an hour then reset  :-/O.  This time around I got my tongue at the correct angle, set it to 5.125 volts and reassembled the unit.  I put it on an electronic load (Kikusui PLZ50-50A) and set CH1 to 30v@3A/90w.  It's been burning in for about 4 hours now without any problems. 
Don't replace the cap, just empty the filter!
 

Offline Marc M.

  • Regular Contributor
  • *
  • Posts: 132
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #556 on: February 27, 2014, 04:32:07 am »
An update from Zeitech. They are refusing to pay for return shipping, saying that Rigol will pay it. Has anyone had shipping costs paid by Rigol?
When I sent my scope in for repair to Rigol NA they wanted me to pay for the shipping to them and they would pay the return shipping.  I asked for them to pick it up both ways since the scope was only a few months old and I've purchased several pieces of their equipment. They went ahead and e-mailed a pre-paid FedEx label.  So I would suggest contacting Rigol directly to confirm that they will pick up the cost of return shipping as Zeitech is stating.  Even if Zeitech is FOS, Rigol may cover it anyway out of goodwill.
Don't replace the cap, just empty the filter!
 

Offline tequipment

  • Regular Contributor
  • *
  • Posts: 198
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #557 on: March 08, 2014, 06:15:40 pm »
There's an EEVBlog discount at TE? How do you get that and how much is it?

5% Discount. just enter xxxxxxxxxxxxx (I think if my memory is correct) I called and asked them for the code. You will enter at checkout in the discount column.

Update: 6% Discount not 5%

Guys thanks for the business but can you remove the code.  We want it for eevblog members only and not posted publicly.. Thanks
Evan
TEquipment.NET
 

Offline tequipment

  • Regular Contributor
  • *
  • Posts: 198
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #558 on: March 08, 2014, 06:17:13 pm »
There's an EEVBlog discount at TE? How do you get that and how much is it?

5% Discount. just enter xxxxxxxxxx (I think if my memory is correct) I called and asked them for the code. You will enter at checkout in the discount column.

Update: 6% Discount not 5%

Guys thanks for the business but can you remove the code.  We want it for eevblog members only and not posted publicly.. Thanks
Evan
TEquipment.NET

I was wrong with the 5% discount. The correct discount is 6%
 

Offline Dave Turner

  • Frequent Contributor
  • **
  • Posts: 439
  • Country: gb
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #559 on: March 25, 2014, 11:40:54 am »
As reported previously in this thread Telonic Instruments Ltd, who manage www.rigol-uk.co.uk as the UK official Rigol distributors, originally delivered a DP832 without the latest fix, but agreed to update my unit when the new boards were available.

I got the call yesterday and today a new unit and warranty card was delivered and exchanged for my old unit at no cost to myself.

My thanks to Dave & Karen at Telonics for their excellent service.

 
 

Offline ivaylo

  • Frequent Contributor
  • **
  • Posts: 588
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #560 on: March 26, 2014, 06:27:49 am »
As I wrote before ordered mine from Tequipment about a year ago. Came a few months later with all reported here defects. Teuipment wouldn't help with the defective unit, sent me to Rigol, fine. Waited a few moths, got a decent Hameg PSU for the same price (from the forum here) and asked Rigol to return the DP832A. They agreed, shipped it two months ago, and they disappeared. Not replying to my emails, phone line always busy, etc. Not even sure if Tequipment is supposed to return my money (they got it initially) or Rigol. Not really impressed by the customer service of either company. It's a clear case of defective product line, solve it among yourselves, and don't make your customers do your work. Blah, rant over...
« Last Edit: March 26, 2014, 07:39:11 am by ivaylo »
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #561 on: March 26, 2014, 06:47:32 am »
...asked Rigol to return the DP832A. They agreed, shipped it two months ago, and they disappeared. Not replying to my emails, phone line always busy, etc. Not even sure if Tequipment is supposed to return my money (they got it initially) or Rigol...

If your intention was to return the DP832A for a refund (sounds that way since you bought a replacement), why did you send it to Rigol?  Rigol could perform repair under warranty, but you would need an RMA before sending it in, and presumably you got one which would have indicated if it was going to be repaired.

It seems logical to return the product to the place of purchase (TEquipment) if you want a refund...

In my case it took Rigol 4 weeks (+ one week shipping each way) for the LM317 heatsink fix, which was much longer than I expected, but it all worked out.

I hope you can get it all sorted out.
 

Offline ivaylo

  • Frequent Contributor
  • **
  • Posts: 588
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #562 on: March 26, 2014, 07:37:59 am »
Quote
It seems logical to return the product to the place of purchase (TEquipment) if you want a refund...
It does seem logical. Tequipment played dumb, wouldn't take the unit back, sent me to Rigol. Rigol issued RMA and took it. Then disappeared.

Quote
In my case it took Rigol 4 weeks
From the moment you approached them (or did they approach you?) or from the moment you sent it?
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #563 on: March 26, 2014, 07:56:44 am »
Quote
In my case it took Rigol 4 weeks
From the moment you approached them (or did they approach you?) or from the moment you sent it?

Neither.  I submitted an online form (on one of Rigol's websites) to get put in a queue and be notified of the board replacement process once it got started.  A few months after I submit the form, I got a surprise RMA via email to send in my DP832A unit for the board replacement.  I sent off my unit, and from when Rigol received it, it took them 4 weeks until I received notice of a return shipment to me.  So Rigol had my unit for 4 weeks, and it was one week each for ground shipping to them and back...so total I didn't have it for 6 weeks.  It was longer than I hoped, but all is good, and no cost to me.

 

Offline Dave Turner

  • Frequent Contributor
  • **
  • Posts: 439
  • Country: gb
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #564 on: March 28, 2014, 04:45:50 pm »
My replacement DP832 shipped with firmware v1.09.

On powering up with no load the temperature on the test-cal screen read 8.22. Note there are no units defined.
Ambient temperature was 17.5C.
After 15 minutes the temperature read 9.70 and 10.44 after a further 1 1/2 hours at which time the ambient temperature rose  to 18.7C.
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #565 on: March 28, 2014, 06:04:40 pm »
My replacement DP832 shipped with firmware v1.09.

On powering up with no load the temperature on the test-cal screen read 8.22. Note there are no units defined.
Ambient temperature was 17.5C.
After 15 minutes the temperature read 9.70 and 10.44 after a further 1 1/2 hours at which time the ambient temperature rose  to 18.7C.

This odd temperature behavior has been noted previously in firmware 01.09, we believe it to be a bug.  See bug 5 in the list, and specifically the posts referred to therein.

>> 5. Temperature reading incorrect in 01.09

« Last Edit: March 28, 2014, 11:53:28 pm by Sparky »
 

Offline Dave Turner

  • Frequent Contributor
  • **
  • Posts: 439
  • Country: gb
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #566 on: March 28, 2014, 10:43:39 pm »
Sparky

Yup, I know it has been reported before. I was attempting to give a little more info in case it is of help to anyone gathering statistics.

 :)
 

Offline Corporate666

  • Supporter
  • ****
  • Posts: 2004
  • Country: us
  • Remember, you are unique, just like everybody else
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #567 on: March 28, 2014, 11:02:15 pm »
I got my DP832 back from Rigol on Tuesday.  So it was just about 3-4 weeks from when I sent it back to when it was being delivered back.  It also was upgraded to firmware 1.09 which I was not too happy about.  Haven't noticed any extra fan noise - maybe even less, if anything.  Also haven't cracked it open to see what is new inside, but the unit seems to work great. 
It's not always the most popular person who gets the job done.
 

Offline Sparky

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: us
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #568 on: March 28, 2014, 11:55:37 pm »
Sparky

Yup, I know it has been reported before. I was attempting to give a little more info in case it is of help to anyone gathering statistics.

 :)

Okay! No worries!  It never hurts to confirm that the issue is widespread, and not isolated to a few units.  Cheers!

 

Offline thmjpr

  • Regular Contributor
  • *
  • Posts: 116
  • Country: ca
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #569 on: April 20, 2014, 11:25:30 pm »
Went to perform mod mentioned by Marc M. and received a small surprise, the fuse on 8V AC input was replaced with a wire. Not a major safety issue, but I can't think of a good reason for doing this.

Replaced with 1.25A glass fuse + dc converter board, seems to be fine.
 

Offline neslekkim

  • Super Contributor
  • ***
  • Posts: 1303
  • Country: no
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #570 on: April 21, 2014, 08:11:31 pm »
Is that corrosion on the screw on back of the heatsink?
 

Offline clivew

  • Contributor
  • Posts: 10
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #571 on: April 21, 2014, 11:22:20 pm »
I wonder what the white tubular component on the output (?) lead is? :-//
 

Offline Rigby

  • Super Contributor
  • ***
  • Posts: 1476
  • Country: us
  • Learning, very new at this. Righteous Asshole, too
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #572 on: April 22, 2014, 02:13:02 am »
Ferrite? Shrink-wrapped by the look of it.
 

Offline thmjpr

  • Regular Contributor
  • *
  • Posts: 116
  • Country: ca
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #573 on: April 22, 2014, 04:13:23 am »
Is that corrosion on the screw on back of the heatsink?
No, something waxy, probably flux. There is also a clear glue that was spilled on the top capacitor.

I wonder what the white tubular component on the output (?) lead is? :-//
Rigby is correct, a few small low frequency ferrites that I slid over the wire. Bit of paranoia from failed EMI tests in the past :).
Since the 5V is just for digital circuitry, I don't think the switcher will have any negative effect.

Similar part: http://www.digikey.com/product-detail/en/74270012/732-3987-ND/3316784
« Last Edit: April 22, 2014, 04:18:29 am by thmjpr »
 

Offline Bomber18

  • Contributor
  • Posts: 12
Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #574 on: May 27, 2014, 02:11:02 am »
The pot on the board was wired as a variable resistor i.e. 2 legs were shorted together.  I set it for 5v, pulled out the pot and measured it right at 1k.  Conveniently, the manufacturer placed smd pads underneath the pot so it was simple to set it to a fixed voltage.  I soldered in a 1k smd resistor which yielded 4.96 vdc out.  Meh, close enough.  I put the power supply back together, fired it up and discovered it was in about a 5 second reset loop  :palm:.  I didn't want to mess around with swapping fixed resistors so I just re-installed the original pot.  I set it for a touch over 5 volts and put it back together.  It was good for about an hour then reset  :-/O.  This time around I got my tongue at the correct angle, set it to 5.125 volts and reassembled the unit.  I put it on an electronic load (Kikusui PLZ50-50A) and set CH1 to 30v@3A/90w.  It's been burning in for about 4 hours now without any problems.
I finally broke down and decided i'd just do the step down repair myself after submitting the RMA repair form to Rigol in November and never hearing back from them and the stories of the 6 week turn around. I was hoping this would be a quick project for the long weekend but between the factory stripped hex screws I had to Dremel out and whatever wiring mistake i'm making it's been anything but.

I've got the points marked on the picture, 1 and 2 are the heat sink connections, 3 is the VAdj or pin 1 on the LM317, 4 is the Output or pin 2 on the LM317, 5 is the Input or pin 3 on the LM317, and 6 is a resistor point which I've seen some people connect to for different mods. I'm connecting In+ to point 5, In- to point 2, and Out+ to point 4.

I feel like an idiot as it seems many have had no issues with this but I'm looking for any advice on what i'm doing wrong here. I have my LM2596 adjusted to a 5.12V output but when I connect it in the power supply the output power at point 4, that is normally around 11V with the LM317, goes low to around 1V which renders the step down circuit useless.

If you noticed the alligator jumper that's from me managing to blow the fuse after I got frustrated and starting tinkering but any advice would be appreciated as I wait for my replacement fuses to arrive.

Step Down Converter http://www.ebay.com/itm/380755874794?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2648
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf