#1563

@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 !

1 Like
#1564

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.

#1566

@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?

#1567

Just attach your Pi with SD card and screw everything together.

#1568

@Shiftr Thanks. So there is no risk that the Pi may have been the cause of the problem? What bugs me, is trying to understand why it happened and not ruin another shield, you see. :slight_smile:

#1569

Seems very unlikely… Best is to do a good visual inspection of the Pi. See if there is no damage to be seen. Or maybe weird debris or solder flakes from the shield.

#1570

Well if you find someone with soldering skills and the correct tools the DAC could be swapped, so I would try contact the original builder, if he built more than one he may have a spare chip. It’s not a route I would totally discard from the start, but if you are looking something easier buying a pre-soldered shield its definitely the way to go. Also notice that you could probably salvage at least (i.e. without de-soldering anything) the Pi, the case and the screen (if not damaged), so maybe you could arrange to buy only a pre-soldered pcb instead of the whole kit.

#1572

What a drag, so sorry to see this,
only other unique factor would be the metal case which creates many opportunities for shorting…

IMG_0234
IMG_02341249×1249 234 KB

Just eyeballing here, but that area is where the 5v rail goes into the codec, right next that pin is a GND that goes to the via above.

If those pins were bridged somehow, I could see some something bad happening. What is curious is that these issues usually present themselves very quickly and not after passing through a few users hands.

As many stated above, we are in wild west Codec sourcing territory, and while I don’t think there are strictly bootleg Cirrus Logic chips floating out there, I do think there are some “fell off the truck” or did not pass QC chips with roads that lead to Ali / eBay

I also don’t think we should put the original builder on blast, as it has passed through a few hands and an issue like this can be resolved privately, however it would be useful to learn the source of that chip so that others who have used these can keep an eye out.

1 Like
#1573

Thanks everyone. I have just bit the bullet and ordered a new shield from monome. Fingers crossed it will all work fine this time.

3 Likes
#1575

There’s a link above us in the thread for an AliExpress source that sells 5-chip packages. I haven’t ordered from him because I only need one or two at most, but others did and looks reputable.

#1576

I’ve finally gotten a multimeter onto this, and whether I’m powering from the Mac or the wall, it’s reading 0 volts. Which seems very strange, because I do see something on the screen. My soldering is a long way from the cleanest in the world but I really don’t think anything’s bridged… ah well.

#1577

which power supply are you using?

#1578

I’m powering it via various USB power sources, not an official RPi-approved power supply, but it isn’t showing any other signs of being power-starved (awake is currently tinkling away).

#1579

I was able to source 10 from this distributor I found on Octopart:

https://www.antdic.com/CS4270CZZ.html

They were $16/each… but for me, it’s worth not having to wait 6 more months. They ship via DHL, so they should arrive much faster than ordering something on Ali Express.

#1580

You could try cleaning all the solder joints with an old toothbrush.

#1581

You’ll need a supply with the correct amount of amperage for sure.

The approved supplies are 2.5A

iPad chargers also work

#1582

norns
norns3980×2985 545 KB

ok, this is very good, just finished building this this morning… it’s amazing that this is available to diy, monome has been on my horizon for so long, but always was hard to jump into. but I started building things this summer(mostly eurorack), and took a crack at this one. this community is so great, really unlike any other which I’m sure you most already know. thanks monome people for being so welcoming and inspiring

5 Likes
#1583

Nice, I’m planning to build from scratch. But the this CS chip! Is there any good solution? From aliexpress is only way?

#1584

I think so, I got mine from a local supplier… but mouser is out till summer or something, further up in the thread tho there is some Ali links

1 Like
#1585

I’m building one for a friend, but I’ve already got most of the parts for it. So don’t what to ask for it.
Does anybody know what all the parts together add up to ?