Author Topic: EEVblog #512 - Rigol DP832 Bad Design Investigation  (Read 244541 times)

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Offline tom66

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #275 on: September 03, 2013, 09:46:17 am »
The main processor and RAM are BGAs. i.MX plus what looks to be at least 16MB of SDRAM going by the package type.

Frankly, you can drive an LCD like that (~320x240 colour 16-bit, non-memory type) from an STM32F4 + 512K of SRAM, so I'm not sure why they bothered with an i.MX... seems a little overkill. My guess is they have a lot of code written for that, and the engineering cost being the main driver of the instrument cost, meant it worked out cheaper. I know they use i.MX in the DS1074Z, and I expect they're slowly moving away from Blackfins as they put more of the processing load in their scopes on FPGAs, or maybe the i.MX has good enough DSP anyway.
 

Offline MacAttak

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #276 on: September 03, 2013, 10:33:39 am »
It seems like simply offering an extended warranty (at no charge) to owners of models with specific serial numbers would also solve the problem. More or less. Yes, some subset of units would still fail (but not all). Those customers would be able to get a warranty repair. And Rigol wouldn't have to issue a full recall. From a customer perspective, this is no worse than a recall... you still have to send the thing back and wait on a replacement either way. And what if some other problem is found in between now and when that regulator finally dies? You get a two-for repair in that case :-+

This is what Microsoft did with the RROD on the original revisions of the 360 if I recall correctly. We just got a few extra years on the warranty - which was more than enough for most people. And even post-warranty, they still would take care of it just to avoid the bad press.
 

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #277 on: September 03, 2013, 10:39:54 am »
From a customer perspective, this is no worse than a recall... you still have to send the thing back and wait on a replacement either way.
Except that it might die a week before a deadline, or some other unfortunate time. In the case of a recall the customer has at least some control about when to send it back, and they can even rent a replacement in advance if needed.

And what if some other problem is found in between now and when that regulator finally dies? You get a two-for repair in that case :-+
Then they deserve to have to do a second recall. That might inspire them to fire those monkeys doing testing and QA and get some actual humans to do it.

This is what Microsoft did with the RROD on the original revisions of the 360 if I recall correctly. We just got a few extra years on the warranty - which was more than enough for most people. And even post-warranty, they still would take care of it just to avoid the bad press.
The Rigol DP832 claims to be a professional tool, not a consumer toy. Being without an X-box for a few weeks is not an emergency for most people. Being without a power supply that was part of a product demonstration might be.
 

Offline Corporate666

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #278 on: September 03, 2013, 10:45:44 am »
Quote
The bigger issue is the one I and others have raised on various occasions recently (and got thoroughly told off for doing so): People need to focus on basic performance of the test equipment they buy first, bells and whistles secondly. Otherwise the manufacturers will focus on making more (inexpensive) bells and whistles, instead of focusing on basic performance (which can be costly to implement correctly).

Ok, but what basic functionality does not operate correctly?  It delivers power within spec and I have loaded it up on my electronic load and it didn't burn up or overheat.  I don't see what Rigol has sold us that the supply is incapable of achieving?  Sure, the power spike at turn-on is unfortunate, but I think it is being overblown.  I measured 1.6V on CH1 and -600mV on CH2 - which IMO makes the PSU unsuitable for only a very small subset of users.  On the other hand, for me, being able to see the output of all 3 supplies is quite important, especially in an R&D/prototyping environment.  I don't think that is ignoring basic functionality in favor of bells and whistles, it's just assigning more value to the features that are helpful to me.

I would agree, that in the current situation the smart move for any buyers would be to do nothing right now, while we wait for Rigol's next move.

I hope we will get it soon.  I got a cheerful call from Rigol's North American customer support/technical sales guy a few weeks ago after I got my DP832 - he was quite interested in making sure we were totally happy since we bought several bits of Rigol gear in the past few weeks.  Let's see if he is equally interested in making sure we are totally happy now that there is a real problem :)

I fear Rigol's response will be to refuse to exchange units with this thermal issue... and I intend to do my best to compel them to exchange my unit.  Hopefully they do the right thing on their own. 
It's not always the most popular person who gets the job done.
 

Offline EEVblog

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #279 on: September 03, 2013, 03:37:59 pm »
I have heard back from John South at Emona about the issue. And I'll quote a few parts:
Quote
we will be getting a detailed response from Rigol in the next day or so . Even with the old boards they have only just today been able to replicate your rebooting . The board out of the case and the higher Aust. Voltage apparently contributed. (As much as working out a solution for existing customers they needed to see what was happening on the original boards

They will be coming up with a fix for existing customers with older boards and it will be sooner rather than later (I expect an answer in
the next couple of days).
 

Offline EEVblog

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #280 on: September 03, 2013, 03:44:52 pm »
We're 240V 50Hz here in Australia. Where I live the mains is usually around 245V RMS.

No, we are officially now 230V + 10% -6%
However, a nominal 240V is still very common, and is what I get at home and the lab.
 

Offline gilbjd

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #281 on: September 03, 2013, 03:46:43 pm »
I have heard back from John South at Emona about the issue. And I'll quote a few parts:
Quote
we will be getting a detailed response from Rigol in the next day or so . Even with the old boards they have only just today been able to replicate your rebooting . The board out of the case and the higher Aust. Voltage apparently contributed. (As much as working out a solution for existing customers they needed to see what was happening on the original boards

They will be coming up with a fix for existing customers with older boards and it will be sooner rather than later (I expect an answer in
the next couple of days).

Thanks for chasing this up with Emona, Dave.

As a recent purchaser from Emona (DP832A 2 weeks ago), I would like to get this design flaw eliminated from my unit. Therefore it would be great if you could keep us up to date with Rigol's response and Emona's response for Australian customers.

 

Offline Corporate666

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #282 on: September 03, 2013, 04:20:03 pm »
I have heard back from John South at Emona about the issue. And I'll quote a few parts:
Quote
we will be getting a detailed response from Rigol in the next day or so . Even with the old boards they have only just today been able to replicate your rebooting . The board out of the case and the higher Aust. Voltage apparently contributed. (As much as working out a solution for existing customers they needed to see what was happening on the original boards

They will be coming up with a fix for existing customers with older boards and it will be sooner rather than later (I expect an answer in
the next couple of days).


Ipad typing sucks..

Dave, how much (or all?) of this info applies only to Australian units?  Is Emona dealing with Rigol china on this or Rigol Australia?

Just wondering if we need to do our own badgering for USA units or if this pending solution will be all-encompassing... Thx!!!
It's not always the most popular person who gets the job done.
 

Offline gilbjd

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #283 on: September 03, 2013, 04:32:14 pm »

Ipad typing sucks..

Dave, how much (or all?) of this info applies only to Australian units?  Is Emona dealing with Rigol china on this or Rigol Australia?

Just wondering if we need to do our own badgering for USA units or if this pending solution will be all-encompassing... Thx!!!
[/quote]

Unlike their presence in the EU and the USA, Rigol has no office in Australia. Emona is their Australian distributor.
 

Offline mickpah

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #284 on: September 03, 2013, 04:32:36 pm »
We're 240V 50Hz here in Australia. Where I live the mains is usually around 245V RMS.

No, we are officially now 230V + 10% -6%
However, a nominal 240V is still very common, and is what I get at home and the lab.

more to it than that, as always the power companies give themselves wiggle room.
http://www.ausgrid.com.au/~/media/Files/Network/Documents/ES/ENOS_Oct2011.pdf
my daytime average is above 245, I strongly suspect neighbours tweaking overvoltage cutout on solar to get max $$$
« Last Edit: September 03, 2013, 04:37:06 pm by mickpah »
 

Offline mickpah

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #285 on: September 03, 2013, 04:35:38 pm »
good to see Emona involved  but I got mine from Eyou http://www.eyou.com.au/
guess that may be a separate battle.
« Last Edit: September 03, 2013, 04:37:28 pm by mickpah »
 

Offline Corporate666

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #286 on: September 03, 2013, 04:39:35 pm »
Unlike their presence in the EU and the USA, Rigol has no office in Australia. Emona is their Australian distributor.

thanks for the info.

Dave when you hear back could you maybe ask if this is a fix for Ozzie units or all DP832?  I think the tests that the yanks have done show its not a 240v only issue.
It's not always the most popular person who gets the job done.
 

Offline John South

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #287 on: September 03, 2013, 05:12:42 pm »
Hi - Just to let you know I am speaking with Rigol China and have passed that info on to Dave. I was on the phone to them today and they will have a resolution within a couple of days. I look after Australia and New Zealand so I will be looking after customers who have purchased from us here but I am sure that there will be similar options (whatever form that will take) available elsewhere . Whatever people think or like/dislike about their product they do take quality issues seriously.

mickpah - We can organise your unit as well. I will send you a pm.
Disclosure : I work for Emona Instruments. We are a supplier of T&M equipment in Australia and are the Australian Distributors for Rigol. www.emona.com.au/rigol
 

Offline tru

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #288 on: September 03, 2013, 05:26:51 pm »
I don't know where you live but in the EU the minimum warranty period is 2 years. Beyond that the UK has something called the Sale of Goods Act, which states that anything you buy must last a "reasonable length of time". For example a laptop computer is generally said to have a five or six year lifespan by the courts. If it dies before then the shop (not the manufacturer) has to either replace or repair it, or can offer you a partial refund based on the amount of time you had it. So for example if your laptop dies after three years you might get 50% of the purchase price back because it only lasted half has long as it should have.

Price is mostly irrelevant. It doesn't matter if the laptop was £150 or £1500, it has to last a reasonable length of time for a laptop. In the case of lab equipment like a £350 PSU a decade would seem like a reasonable period to me. Lab use would be at least 8 hours a day, five days a week.
What are you smoking? (joke), but seriously what you're saying is untrue in the UK. Uk is no exception, UK Courts are held on an individual basis and results are also and are not automatic, final results depends on the judge, etc. Also it is not free, you would need to hire a Solictor (£££) to conduct the legal work and it most likely costs more than buying the new product.

Where is this link/reference of such 5 to 6 years law claim?

Warranty void labels do hold in the UK as it is not even mentioned in the "Sales of Goods Act".
 

Offline EEVblog

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #289 on: September 03, 2013, 06:31:42 pm »
The sticker may help them to show you opened the device, but they still have to prove that the specific fault was caused by you and was not there when the item was sold to you.

"I present as evidence to you your honour, this 45min video from a crazy aussie bloke that proves it is a design oversight"  ;D
 

Offline tru

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #290 on: September 03, 2013, 07:25:04 pm »
I guess you have no experience of this. You don't need a solicitor, you can use Small Claims Court. It costs £30 but you get that back if you win.

The warranty label is meaningless. The burden is on the shop to prove, on a balance of probabilities, that the fault was not a manufacturing problem. The sticker may help them to show you opened the device, but they still have to prove that the specific fault was caused by you and was not there when the item was sold to you.
Nope, I've never used Small Claims Court, and where does it say it costs £30?  In their link:
https://www.gov.uk/make-court-claim-for-money/going-to-court
All I see is:
"If there is a hearing, you can:.... pay for a solicitor to represent you"
Suggests paying yourself which most likely more than £30 if it goes further.

Yes, I'm not saying that warranty void label will stop you from particular case of manufacturing problem claim, but I disagree that it is meaningless in a court system.  In cases such as wear & tear/breakdown/accidental damage goods and under warranty, a warranty void broken seal will lower your chances.

Dave's case is about manufacturing problem/design fault, not your every day general case.
« Last Edit: September 03, 2013, 08:02:03 pm by tru »
 

Offline mickpah

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #291 on: September 03, 2013, 07:33:53 pm »
We're 240V 50Hz here in Australia. Where I live the mains is usually around 245V RMS.

No, we are officially now 230V + 10% -6%
However, a nominal 240V is still very common, and is what I get at home and the lab.

more to it than that, as always the power companies give themselves wiggle room.
http://www.ausgrid.com.au/~/media/Files/Network/Documents/ES/ENOS_Oct2011.pdf
my daytime average is above 245, I strongly suspect neighbours tweaking overvoltage cutout on solar to get max $$$

However, Ausgrid aims to maintain supply within the target steady state supply voltage range for at least 98% of the time when measured over a period of one week.
Which equals up 210 minutes consecutive or in intervals allowable above 253 v to meet targets - they are likely better than that, prudent design would need to take this into account
 

Offline lemon

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #292 on: September 03, 2013, 08:52:35 pm »
I have confirmation that the issue has already been fixed in a new board revision.
They changed the board to fit a larger heatsink, but it's not a huge amount bigger. See photo.
They measured the temp at 76C in a 28C ambient , but I'm not sure if this is free standing out of the case, or in the case with airflow.
They will be replacing all Australian units, I don't know about other countries.

I would not call this a proper belt'n'braces fix, as I think the heatsink still isn't big enough, but it probably now puts it into the (just) acceptable category.
They have also apparently made a few other fixes.



Do you know from what serial number done this new board revision?
 

Offline EEVblog

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #293 on: September 03, 2013, 09:44:44 pm »
Do you know from what serial number done this new board revision?

That is unknown at this stage.
Should be visible through the vent holes though.
 

Offline AlfBaz

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #294 on: September 03, 2013, 11:08:30 pm »
...They have also apparently made a few other fixes.

From that picture it looks as though they have moved those other caps (just visible on the left) further away from the rectifier heatsink

EDIT: Just looked back at Dave's video, the gap was bugger than I remembered, so no...
« Last Edit: September 03, 2013, 11:11:56 pm by AlfBaz »
 

Offline HackedFridgeMagnet

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #295 on: September 03, 2013, 11:17:56 pm »
Quote
EDIT: Just looked back at Dave's video, the gap was bugger than I remembered, so no...
Freudian slip maybe, nice one.
probable version: "bugger the gap was bigger than I remembered"
 

Offline AlfBaz

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #296 on: September 03, 2013, 11:20:36 pm »
Freudian slip maybe, nice one.
probable version: "bugger the gap was bigger than I remembered"
LOL, took me a minute to see what you meant :)
 

Offline EEVblog

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #297 on: September 04, 2013, 12:06:16 am »
EDIT: Just looked back at Dave's video, the gap was bugger than I remembered, so no...

Ah, so you're really a New Zealander  :P
 

Offline nquantum

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #298 on: September 04, 2013, 03:04:19 am »
After read topic since 1st page up to now. Wondering who already own this unit and confirm this heat problem? More important is what u gonna do next? U wait for Rigol to respond or u will modify by yourself/how.

I'd also specially ask Dave. What u gonna do with your unit? Since u already break the seal so u break warranty right? Or if u don't break the seal yet. What u will do with this heat issue? I'm in Thailand. I also interest to have this unit in next 2-3 month also.
Thank
 

Offline Kjelt

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #299 on: September 04, 2013, 05:05:09 am »
The Rigol DP832 claims to be a professional tool, not a consumer toy. Being without an X-box for a few weeks is not an emergency for most people.
Tell that to your kids and see what happens  :D
 


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