DIY: norns shield

[tehn]

group-buying a bunch of boards is sortof antithetical to this whole project.

the main reason we sell kits is so you don’t have to spend time organizing manufacturing at a scale that’s less effective that how we do it. we do not make a huge profit on these, and the profit we do make furthers the mission.

if you want to DIY, just do it for real: just get a board via oshpark/etc and learn to solder. it’ll be a far more rewarding experience. this is why i open-sourced the boards in the first place: to allow people an inexpensive entry into the project, with the trade-off of some degree of self-education.

[quirklebit]

I’m sorry, I know what you mean. Consider the group order cancelled - I don’t want this to annoy anyone. Thanks for making that clear!

[neronoia]

Hey guys, does anybody have a reputable source for buying the DAC chips in Europe? I got one on Ebay but it’s the wrong one

[misuba]

So when I first built it from the kit, my shield worked great. I concentrated on other stuff for a few months and now the screen is so dim it’s barely visible. Anything that’s not full brightness isn’t visible at all. Also there’s a funny extra-pixelated look that I suspect is the result of the lower brightness.

I’m the first to admit my soldering isn’t super clean, but I’ve re-flowed all the header connections for the screen and re-seated everything, and no change. Any advice?

[alley_cam]

I’ve haven’t encountered that issue before, but you could check the voltage on pin 2 of the display if you have a multimeter,

Should be ~ +3.3V

Pin 1 is a GND

If you are looking down at the shield, Leftmost pin is Pin 1

[Prophane]

Hi everyone. So I got this Norns Shield pre built on Reverb, and after 3 days of light use, this morning it started behaving weirdly, sound sort of came and went, then just went. A did a couple of restarts and changed script to be sure, and the same happened. Then, on the third attempt, the unit smoked from the back and froze for good, and it is now dead. The seller has been helpful but obviously, it was working when he sold it to me, so…tough luck.

I’m unsure what went wrong, my power extension is surge protected supposedly, and although I did not have any other hardware switched on, my studio monitors we on and didn’t have any issues at the time it happened.

Now my question is : is it worth purchasing a new Raspberry Pi 3 Model B and try to replace the old one? How can I test that the norns itself (I lack the technical vocab to actually name it) isn’t also damaged?

Has anyone else ever had such an issue, a fried Shield or I am the first ever??

What would you experienced users do?

I mean, I bought this to make lockdown creatively awesome, but now lockdown is likely to make it difficult to be repaired…

Thanks for your time.

[jmsiener]

That is odd but at the same time nothing I’d say you’re not particularly responsible for. Did the builder provide a case or you after the fact? Just curious because part of the circuit touching something could be a short potential that a case would prevent. Have taken the unit apart to see any obviously damaged components?

Without knowing if it was the pi or shield that failed adding another pi could just fry a different pi if the problem is the shield. There’s a lot of weird situations where some minuscule whisker of solder can move over time and become a dead short. Or a cold joint that initially worked but has now failed over time especially if the builder was in a different climate (for example, building something in the southwest and sending it the northeast where humidity is insane in comparison). Without knowing the state of the shield I wouldn’t try anything else; it’s a dud for the time being.

I’ve built well over 200 euro modules at this point as well as several desktop projects and haven’t sold one of them because I believe as a builder you should provide some sort guarantee and if you can’t that probably says a lot about the quality of your work. I know that’s a tall ask but 30 days at least isn’t crazy. If what you built can’t hold up to regular use then maybe the builder should revisit it.

If you’re up to soldering, can disassemble the board, and provide some high res, close up images I’d be willing to take a look but there’s no guarantee me or anyone else would notice the fault with naked eye and no meter.

[Prophane]

Thank yiu for your reply. It is pre built in an aluminium case. Jack who sold it to me here in the UK, says he bought it from Belgium from a gent named Gregory, I am not sure how long ago. I’ve taken the case off and I cannot see anything specifically wrong at first sight. It did stay in my studio overnight, the heater set at 10 degrees Celcius. Apparently there were issues with Oled interference noises that were not mentioned at time of sale, but it appears to be a more common issue that has been previously discussed in threads.
What kind of meter is needed to figure out if the shield still works?

[tomw]

If you haven’t already, my first step would be to take it out of the case, take the norns shield off and just plug the raspberry pi into the power and connect the HDMI to something. If the pi is still working you should see the rainbow square on your monitor/tv. You could download raspbian onto an sd card if you want to test it more thoroughly but that should tell you if the pi is still working or not.

[jmsiener]

Really any meter with a continuity tester that beeps will work. On the shield look for shorts between either the 5V or 3.3V power lines and ground. If it beeps or reads a really low resistance (<1k ohms) then you know there’s a short and a dead short on the power rails is about the only thing that would really make an IC release the magic smoke.

[alley_cam]

Very curious about this. Could you snap some pictures of the bottom of the shield board? Thank you!

[Prophane]

[Shiftr]

Wow! Kind of beautiful … It’s the DAC. Really strange to have that blow up like this.
Should be replaceable by someone with solderskills.

[wheelersounds]

Also, ideally the person who fixes it can diagnose/fix the cause of the issue, too. I’m sorry you got a bum deal. I’m in the states so it’s unlikely that shipping would be worth it, but lmk if nobody local can help and I’ll see what I can do…

[Prophane]

@Shiftr Hey thanks for this info! So assuming that could find someone with the soldering skills (anyone into eurorack diy could do this maybe?), where do I find a replacement DAC? (what does DAC stand for, may I ask?).

@wheelersounds Wow, nice one, thank you very much! Let’s hope I can get it back to life soon. It’s a full lockdown here in the UK, so assuming I find someone, it might not be quick whichever way… But I will try (although my thoughts this morning were to simply order another shield from monome, since they say that no soldering skills are required… I just had about enough time to fall in love with 3 scripts and I miss it already!

[Shiftr]

Digital to Analog converter. Actually it’s a DAC and an ADC.
It’s this part: CS4270-CZZ Cirrus Logic - CODECs - Distributors, Price Comparison, and Datasheets | Octopart component search
It’s a bit difficult to get hold of this part but you can find it on ebay and aliexpress. There are some links in this thread.

Or you were really unlucky and had a bad part or there was a tiny solder flake somewhere that made a short through the chip. Well that’s what i can think of.

Getting a monome one won’t hurt. And you can get this fixed when you want your second Norns. ( That happened to me )

[sademik]

hi there @Prophane

from what i understand, the CS4270 DAC is a hot commodity at the moment. it may be a little while until you’re able to get your hands on a spare to replace yours with. here is a seller that was confirmed working above in the previous posts. reported working CS4270 seller

edit; slightly redundant with the post from @Shiftr but the more the merrier!
i’d also like to mention its possible that yours could have possibly been built using an illegitimate CS4270, which could have caused your issue

[Prophane]

@Shiftr Oh yes, right. I knew what a DAC was then, I just somehow didn’t put A+B together! About ordering a new one, I’m just a bit weary now, understandably I guess. I’m thinking I might be better off investing in the Norns at the end of February, for peace of mind.

@sademik Thank you !

[neronoia]

DAC means Digital-Analog Converter, and it’s the chip responsible for converting audio signal back and forth from digital and analog domain. Arguably the most critical component in the Shield since all the processing operations are done by the rPi, and the shield “just” provides conversion, the physical ins/outs, the encoders and button and the screen.

As for where to find it, that’s the problem. They are currently sold out all over the usual european/western retailers, and most people building it from scratch in the last few months are resorting to AliExpress or chinese ebay sellers. The problem is that those retailers have a lower tolerance for faulty/bad chips so you are supposed to buy more than one and test them out to find one that works reliably. For example one friend of mine bought 5 of them from Ali and out of those 5 only 2 worked, and if you do not have the correct de-soldering tool (hot air gun) removing one from the pcb is basically impossible, so a new pcb must be used for testing each one. For example I an building one, since I screwed up the crystal on my previous build, so I’m just waiting for any reputable retailer in Europe or for somebody that has one and can sell it to me directly.

[Prophane]

@neronoia Well, thanks for this info. I don’t think I’ll bother joining the queue then…
Is the shield currently sold on the monome website any different, in the sense that the say it requires no soldering, just a screwdriver… I assume it means that all the elements are already soldered and it’s possible to just add the Raspberry Pi and Micro SD card that remain working? Or is it a risk/more complicated than that?