Beware of NAD M3 Fire Hazard

With the cheaper NAD range yes, but Master Series stuff competes alongside products from companies with great aftercare.
The M33 was on my shortlist, but after reading this I will go with Lyngdorf 

I’ve had NAD BEE units, of various iterations, for 15 years, and never ONCE had an issue with them. In fact, I recommend them to friends, 4 of whom have had their units in their stereo systems for 6 or more years, and even now, nary a problem.

Certainly, it’s understandable why you feel as you do, but isn’t this a bit like being thrown off ONE American Quarter horse (the most docile and recommended for first-time/beginning riders) and vowing never to get one one again because the first AQ horse was a bad experience?

What happened with your NAD can happen with ANY amp, friend. Don’t lose yourself in the delusion that it can’t. I had two extremely expensive amps blow (not in the same way, but still - they BLEW!)

That said, given the PTSD you’re having, a different amp would be the most logical course of action.

Disappointing reply by NAD. I have read similar issues, if rare, so i guess they dont read forums.

DON’T buy secondhand NAD no matter how old

The newer NAD products, users have reported reliability issues as posted in the forums over a period of time. They, NAD rested on their earlier reputation of building reliable good sounding units for the money which is certainly not the case now for some units.

After some research it appears the M3 was designed by NADs director of  advanced development, Bjorn Eric Edvardson in China.

It also appears that there is not too many reported issues other than one I could find which was described by the owner as switching to stand-by mode while listening to music or switching off while in standby mode. A tech posted that he thought a leaky capacitor in the protection circuitry was the issue.

The lid was off. Tampered? Depends on whose defining it, lol

No manufacturer is going to warranty something that has been tampered with. But its also easy to ascertain that such a thing happened. If it were me, since the unit is worthless as it now sits, I would send it to them with a note explaining that perhaps they could examine it and make a determination (with documentation) as to why they think its been tampered with. At that point you would be rid of it unless they saw clear to sort it out; if not in warranty a repair estimate should precede that.


At least in the case of my car, dealer/manufacturer repairs to it are not more expensive than an independent shop. If that amp was doing the job for you the cheapest way though this might simply be to get it fixed correctly.

Well I tried. Here’s nad’s response:

Unfortunately, as this amp appears to have been bought second hand through a non-authorised reseller, we cannot verify its past history or conclude what alterations or repairs may have been made to the amp before you received it -- all NAD product sold from authorized retailers are given a full Quality Check before resale which is necessary, whereas when bought elsewhere we cannot guarantee this. We have not heard any other reports of this sort of event happening with the M3.

I'm apologise that I am unable to help further, but please let me know if you have any further questions.

Kind regards,
Sam R.,
Support Crew Analyst

Yeah, but that pic man, it shows sprayed cap juice everywhere.

Yeah, its a mess. I've cleaned that sort of nastiness up before. If this were my unit I would be fixing it; replacement is going to be a lot more and unrepaired its worthless. But I understand being gun-shy too.

The previous versions of my NAD C272 also had exploding caps (currently not in use but has worked well).  Turned out to be cheaply sourced capacitors.  Possibly they did not learn from that mistake.  

pwb -- To me it seems obvious they are shining you on. You now have my permission to be like your blown cap and flame the hell out of the company.

"The only likely cause for a power filter cap blowing like that is a power surge issue or a mechanical short. The only incident like that I have experienced in decades of commercial installations was when high voltage showed up between neutral and ground on an AC outlet. "

The power surge taking out the diode bridge and allowing AC into the capacitor..

Interesting...I owned a repair shop for 20 years or so way back, when 8086 8088 processors were everywhere.  There was a  3 phase transformer above the one that feed the shop. Everyone around the shop with PC, would loose power supplies, TVs up in smoke, Everything except the store. I had Topaz line conditioners in the shop..I mean top of the line at the time, FREE. got them out of a hospital closure.

They (across the street) had a thing called a Delta stinger, a Large welding / fab shop. One leg was 208-220, I think.  The other two were 110, 220 between the two 110-117 . It was so they (not me) had 480 for their welding shop.They had a transformer in the facility also. 
I'm kinda close on the description. That big transformer shared a common leg, up on the pole I don't recall just how. BUT at night I saw a little light show between the two. I called PGE. they ran a tape on both sides of the Topaz units. Before unit and after. 135-165 VAC spikes whenever they were welding with certain rigs, across the street.  The Topaz units worked perfect. No brownouts no, Overages.  PG&E paid for anyone that had complained. Something to do with that delta stinger setup, the PG&E guys said.. At my house back then, hovered at 105 then spike at night. All fixed now, but dirty AC all kinds of problems, ay..

Regards

The big takeaway for me in this discussion is that I MUST remove all of the explosives I have stashed around my hifi amps...I'm going to put them in my stove.

Hi thanks for all the responses. I’ve contacted NAD several times and received this response:

Mar 17, 9:30 AM EDT 

Hi Patrick,
Thank you for contacting NAD Support, and sorry for the delayed response.

Please provide me with the Proof of Purchase of your M3, as well as the statement from the Authorised Service Centre in regards to the M3.

With these I may look into this further.

Thanking you in advance,
Sam R.,
Support Crew Analyst

I sent my Audiogon invoice and United Radio invoice that said “not repaired” and I keep getting the same request (5 times) and I responded each time and then received this response:

Your request (#173469) has been pending for 4 days and has thus been solved. To reopen this request, reply to this email or click the link below:
https://support.nadelectronics.com/hc/requests/17346

Any suggestions? Thanks 

I know someone that does component level board repairs, lives close to me in the central NJ area. If you like, I can pm you his contact information.
I've recommended him to several friends, he'll look at your electronic component and will only charge a fee if he's able to fix it.
He's fixed multiple things in the past - tv's, amplifiers, pre-amplifiers, radios, etc. - his shop is pretty amazing.
Hope this helps, Thomas Foti.

Done. 

Also see this thread. https://forum.audiogon.com/discussions/nad-m3-non-repairable

I'd be fuming as much as the amp.
Will mention this on their IG or FB page. 

Was it in use when this occurred?

It makes sense to contact NAD about the failure.  If they do nothing, you aren’t in any worse situation than you are now.  And, as others noted, they might offer you a deal on a replacement.  Word of mouth and promoting good will with customers does a lot to generate new and repeat business.  Certainly worth a try.  This would suck for anyone.  Hope your luck improves.  

but even if a shorted rectifier allowed AC on the cap without shorting out the power transformer's winding, downstream caps might be just fine as resistors are in the circuit that could have limited current.

Yeah, but that pic man, it shows sprayed cap juice everywhere.

I've owned three NAD pieces in the past.  All died premature deaths.   For me, NAD now means:

Never Again Daddio

If this was a serious problem with NAD products we all would have heard about it long before this.


Its very possible that the cap failed without provocation (such as from a failed rectifier); once having developed a source of heat internally it becomes a vicious cycle that goes into thermal runaway until something gives (which is usually at the other end of the cap).


So it might be that replacement of this part and cleaning up the amp is all that is needed, but I would not run it again without having replaced all four filter caps. Caps that are downstream of this particular part may well be just fine- much depends on what the failure mode is (so that should be investigated first- see if there is a failed rectifier), but even if a shorted rectifier allowed AC on the cap without shorting out the power transformer's winding, downstream caps might be just fine as resistors are in the circuit that could have limited current.

The only likely cause for a power filter cap blowing like that is a power surge issue or a mechanical short.  The only incident like that I have experienced in decades of commercial installations was when high voltage showed up between neutral and ground on an AC outlet.
Check your power outlet with a ground fault detector, on of those little 3  light plugs.
With a volt meter test outlet voltage between hot and neutral, then hot and ground. Both should be the same and less than 130v max. Then test from neutral to ground. Ideally there should be no voltage, but often there is a little bit.  To blow a cap like that it would have to see a reverse voltage spike significantly higher than its rating, typically more than 250 volts. Lightning surges coming in on grounds are a common cause. Surge protectors don't typically protect against reverse voltage on ground.

The same thing happened with my NAD integrated amp about 7 years ago, I don't remember the model number but it was 150 or 200 watts a channel and luckily it happened when I was in the room listening to music- flames/sparks shooting up through the top plate ! NAD replaced  the unit for free and I don't recall if it was even under warranty at the time. 

I'd contact them first to see what they'll do; my guess is they'd service or replace it at no charge. 

"Could be anything, but a shorted (Zener?) diode in the bridge passing AC and cooking the capacitor would be my guess."
I agree with the above.

As far as the voltage I am just guessing it is 110. I thought everyone is either 110 or 220

A G R E A T many devices today are still rated 117v. [NAD M3 is 120v]

120v became the US standard in 1967. 120v +5% is 126v which is 107.6% of 117v. It’s not much of an issue for solid state gear with regulated supplies, but in tube, particularly vintage, gear the extra volts can come very close to cap ratings. A Bucking Transformer to lower the voltage to rated is a handy toy. See http://www.ielogical.com/Audio/BuckTrans.php

It’s always a good idea to have a volt meter displaying voltage. A Kill-O-Watt or similar is close enough. Verify with a calibrated Fluke or similar.
D O N ’ T use is as a power meter, except for light loads and brief times.

Back in LA, we had line voltages meters in the studio. No point trying to record if the voltage was all over the map or dragging down to a brown out. Ditto listening to the HiFi.

 As far as the voltage I am just guessing it is 110. I thought everyone is either 110 or 220. 
  
Well mine stays a 117 via variac for the older stuff, (I use seldom anymore) or 120 for all the new stuff on the button. Maintaining 120 VAC is VERY important, brownouts use to be the number one killer of PS in this area (Bay Area). They would hoover at 105, till night time came then they would spike. New 20KV line upgrade from 8KV, night and day.. I hadn't lost a piece of gear in YEARS (35) till just the other day, bone head move on my part..Couldn't STOP the burning because of the conditioners, never happened before..

The little Wyred4Sound SX1000 (I think) when it popped a cap, nothing like this guys for sure.. I still have it, I was gonna swap the ICE board..
PE had them in stock..


Regards

I just looked at my audiogon history and I purchased the amp in august 2012. It was probably no more than a couple years old and in mint condition. Never had any issues with it and it was used sparingly in a second system. As far as the voltage I am just guessing it is 110. I thought everyone is either 110 or 220. 
I sent 2 emails to Lenbrook yesterday but have not received a response.

millercarbon3,411 posts03-16-2020 11:09amThe more time passes the more the first two posts are looking better and better.

Man oh man your just awnry, millercarbon.. It's almost funny but I stop shy of my amps fraggin' the joint. Look like a # 9 went off in there. Self destruct button.. That was bad...

Regards

heaudio123109 posts03-16-2020 6:18am"If they don’t I would post it here for the world to know."

Shaking down a supplier for a 10+ year old+ electronic product, with a history you don't know (not the first owner), that could have experienced surge events, or other events outside the suppliers control, is not cool.

Well the question is, WHY? No matter the answer, shy of "I dropped a penny in the slot, and tried to recover it with a screwdriver and up she went".  That type of failure in that picture is a BIG problem, that was and is unsafe.
Product failure is part of most electronics. Somewhere along the way they usually quit working. EXPLODING is not normal, simple.  I bet they'll want to see it and figure why. I would hope so.. Burning down the house, THAT'S NOT COOL. It should have failed SAFE..RIGHT?? It gets in our homes because it's safe, not UNSAFE.. That's not my opinion, it's the LAW...Yup I get pretty passionate about house fires, neighbors house had a fire  behind a non grounded wall clock power cord, in a finished basement. The electrical was in conduit and grounded propper, if it wasn't for the dogs, the whole house would have went up..
Wall clock???yup breaker didn't pop and the cord caught fire. Out of their home for a YEAR... 

I just glad everyone's ok, where your at..I just went through a 20 amp breaker pop. Trust me it was an expensive POP..

Regards

The more time passes the more the first two posts are looking better and better.

Shaking down a supplier for a 10+ year old+ electronic product, with a history you don't know (not the first owner), that could have experienced surge events, or other events outside the suppliers control, is not cool.

 +1

I agree... you should have contacted NAD as soon as this happened. If *I* was NAD, I would want to know about this right away so that I could try to make it right. 

I had something similar happen to my Porsche 10 years ago. I had just purchased a 2003 911 Turbo in 2010, it had about 32k miles on it, and was bone-stock; the car was now 7 years old, and well out of warranty. After 2 months of ownership, while accelerating (normally) from a stop light, the engine died. Come to find out, a timing chain had snapped, and the whole engine had to come apart. I made the mistake of reaching out to several different people and shops, including Porsche. Porsche of America got back to me, said they had only ever heard of this happening maybe 4-5 times, and offered to cover the tear-down, diagnosis, and  rebuild of the engine!!! However, I already had it at a independent shop, and they had already torn the engine down (prior to my approval to do so, actually...), so I was out any sort of charity repair work from the manufacturer.

Moral of the story, always talk to the manufacturer FIRST. Worst case scenario, they apologize and send you off to invest in another brand.

Please keep us posted though, I'm very curious about what they will say...

- justin

How old is the unit ?
why not call Nad and ask to speak tothe sales and marketing rep . If he cares about the companies reputation 
then he will want to help making things right . This approach makes sense.

Hello, 
I agree with contacting NAD as long as they cover the shipping. It looks like a swap of all the boards is the only real fix. If I owned NAD, I would give you credit for a new one and figure out what failed on the old one. Hopefully, the OP would come back to this thread and note they stood behind their product. This would make it Ok for me to buy NAD. If they don’t I would post it here for the world to know. Anything can happen to a piece of electronic. What is most important is do they stand behind their products and was this a one time occurrence. Sorry for the loss. This is why I prefer separates, but I do get this was not your primary system. 

Dump this unit asap as its pure garbage.Good luck

Sorry for your loss.  The picture was truly worth a thousand words.  NAD should give you some help.  They might not replace it, but should offer you a steep discount on a current production model.  Keep us informed.

I won't derail the thread, but .... this is the perfect example of why you should never remove the ground pin on an AC plug.

Failures are rare but they do happen.

This case wasn't probably caused by a bad ground pin, but this kind of failure can happen and you want the chassis to be grounded by a big beefy conductor when it does.

ejilf  +1

The local line voltage is 110

The unit is rated 120v. Nominal is ±5% - 114v to 126v.

Running on 110v increases cap ripple if load high current delivery is required. Ripple increases heat. By chance did the unit smell hot?

Diodes usually fail open circuit

ESD often causes devices to fail as a short. A puddle of molten silicon makes an excellent conductor.

The only caps I've ever seen 'blow' have been due to reversed polarity. 

Failure analysis is often pure speculation... unless someone 'fesses up <:-0

I had an Innersound amp completely melt down.  Luckily it was in a pretty heavy chassis so the fire stayed inside and didn't burn my house down.  Innersound was out of business so no recourse but on something like that NAD should just get you set up with a new amp, doesn't matter if it's in warranty or if you bought it used.  That should not happen and if it does they should cover it, they are a big company.  Let us know what they say. 

You can see that one or two of the other 80V caps are ready to pop.

Run too close to the voltage limit. they were getting gassy.

A manufacturer of those caps was absolutely full of it, or a parts supplier for that capacitor company was full of it, or..NAD was penny pinching and purchased dicey product, or the capacitor manufacturer flat out lied their face off about their quality standard.

Or some combination thereof. All I can say is that some of the decisions made, from/during that time period, have really hounded the company. eg, the 370 and associated power amp design...I’ve seen far too many of them with the same failure. Additionally, with shorted/dead caps, from the same company/source. Four in one year. I expect to see more.

It is many years down the road, though, so not really all that predictable. But there is a time to be careful about expenditure and a time to throw the penny pinching accountants out the nearest window.

My Best quick guess is that someone decided to try and save a nickel on capacitor costs, and took a shot, they took a swing, they took a flyer... and it worked.

For a while. for about a decade. Now that accounting decision has come back to bite them a bit...

Anyway, no one is perfect, and other than this blip, NAD has done really well. Sooner or later all manufacturers get bit by this sort of thing. It is just a matter of time, but is also tied to design and parts decisions. and it is not always the engineer or designer at fault. It can be accounting that is tied to parts costs, which can make iffy decisions. To do the right hing and satisfy customers who know little about the insides.. but.. a lot about prices they pay. It's a difficult balance at best.

WOW, I thought I had a bad one. Man oh man, it looks like the cap next to it was starting to swell also, I can't see the tops very well. I had a Wyred 4 Sound, 1000 (no R) bought used, blew a cap on one MB. 
The guy was running them on a single, 15 amp outlet. I suspect that caused the problem.  BIG BASS HEAD...I find out after the fact...

That would be a nightmare to clean propper, much less fix and not worry about it.. Sorry your traumatized buddy. That amp will leave you with nightmares. I just had valve amps kick a 20 amp breaker and fry. Must be an electrical virus. LOL it's not funny, I'm walking around swearing, with you for SURE.. Mine was self inflicted, yours..Geez ma neez..
Time for a change.. But NAD!! They have a good product. 

Respectfully and with regard

Diodes usually fail open circuit, unless the heat is so bad that the entire junction completely melts.  The only way that could happen is if the AC supply surged tremendously.  But then again, if that happened, you would have noticed other stuff breaking connected to the AC.

Was there anything on top of the amplifier which could have fell in (even a strand of hair) and shorted something ?

It could simply be a bad capacitor, from the factory. Although very rare, these may still happen.