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Hi guys, I’m in the same boat as the others posting here, I just finished assembling the PCB and the power light comes on and it appears inert otherwise. I’ve tried putting a jumper to one of the pins on the volume pot and as soon as I touch a jumper to the volume it starts buzzing, but that was the only sound I’ve gotten out of it. I had a bunch of 386 chips so I tried a different one, no resuits. I took a long hard look at all my solder joints, tried touching up a couple, no results. I have a version 3.0 board and my serial # from my sticker is zd4847. The only way I deviated from the instructions in the PDF was I put in sockets for the ICs instead of soldering them directly to the board. I think I did this and everything else correctly, not positive. Any advice?
OH hey, here are a couple pics of my soldering from last night. If you spot anything let me know. I’m willing to get a USB Tiny as well if that advances the cause.
[img]https://i.imgur.com/l1zZsuA.jpg[/img]
and
[img]https://i.imgur.com/MuHDwIC.jpg[/img]
Well it looks like those tags don’t work but anyway, you can open the images in a different window or whatever.
Thanks for the photos. It looks like a lot of your solder joints should be reflowed. I would reflow all of them for good measure. Use a bit more heat (leave the iron on the joint a bit longer) and less solder this time.
Your power amp chip is working because you get a buzz on the speaker when you touch the pins of the amp chip. The problem is on the digital sides somewhere. How is the 5V power rail?
-BrachOkay, I have reflowed all the joints like 3 times, finally got it working! Turns out I need glasses and magnification when soldering, I found a lot more joints that didn’t look good that you can’t see very well in the photos. Just wanted you to know, it’s up and running and I plugged the Altura in to it last night and got them working together. So thanks so much!
Hey Zeppelin Design team! I’m also having some trouble getting sound from my synth. It’s my first kit so it may be user error. I have tried reflowing some of the resistor joints, as they were the first and worst I had soldered (some have a bit too much solder now). I also may have slightly damaged the PCB at the ISP, maybe damaging the MISO, SCK, and RSTI side. Not sure if that can cause issue, if so, is there anything I can do about it? I purchased a USBtiny and flashed the software. I can bridge volume pot pins and get a slight buzz, but I didn’t test it for long. Im attaching some pictures, can you take a look?
Solder Side – https://ibb.co/WnL6bkF
Component Side – https://ibb.co/JcGVJkr808ROSS,
Thank you for the photos…they are worth at least 1000 words.
From what I can tell from the photos most of the joints seem like they could use some re-flowing. It looks like you might need to turn up the heat on your soldering iron. What kind of solder are you using? Lead/tin solder is the best and easiest to use. Lead-free solder is much more difficult to get to flow correctly and requires much more heat.
If a joint has too much solder on it, then use a solder sucker and remove most of the solder and then re-flow it.
The solder that you should be using has a “rosin core” in it, which is what we call flux. It’s the stuff that allows the solder to flow smoothly and easily. So, when you re-flow the solder joints you aren’t trying to add more solder to the joint as much as you are really just adding more flux to the joint to get it to flow better. You can get containers of just flux; often they come in a pen or marker form so you can “draw” more flux on the joint before you heat it up…but you don’t need that in this case.
I can’t quite see the details of the ISP pins. I can’t see how you might have damaged the PCB there. You can use your continuity tester on your multimeter to check to see if any adjacent pins are connected (they shouldn’t be). Also please check to make sure they aren’t shorted to the ground plane. There is only one ISP pin that should be connected to ground.
When you flashed the software, did the computer say it was able to connect to the microcontroller and was the flash successful?
The fact that you are able to hear something when you short the volume pot pins means the analog section is probably working fine. The problem is probably with the digital circuit.
Keep me posted.
-BrachHey Brach, thanks for the quick reply on such an old thread. I am using lead free solder. When reflowing the resistors I did turn up the heat some more and did get better results. I also do have flux (in syringe form!) and used it to help reflow the resistors. I checked for continuity on the isp and didn’t find any pins bridged, but I did not test for unwanted grounding. When flashing, the pc did say it successfully connected and successfully flashed. When I get home tonight I will go ahead and remove excess solder and reflow all joints and update you. Thank you again for the guidance!
808ROSS,
If you were able to successfully re-flash it then the ISP header must be working properly, so no need to continue testing it.
For lead free solder you should have your iron set to at least 350 degrees C. Depending on the type, you may need to set it more in the range of 370. Keep in mind, the extra hot temperatures are more prone to damage the board or the components so use your flux so the solder flows quickly.
Good luck!
-Brach
You might consider putting up a photo or 2, that helps diagnose stuff but that said, I had to reflow a couple of these, I’m not all that good at soldering I guess. And it has worked.
So good news. I finally got around to reflowing the joints. First I tried resistors, no luck, then the rest of the joints, still nothing. I tried again today and reflowed most joints, really paying attention to any that didnt look like a picture of a good solder joint. Still nothing. Feeling pretty defeated and frustrated, I went to short the volume pot again to make sure I didnt damage that circuit while reflowing, and I got a very transient, louder buzz, and then the keys started working. It seems like the pots arent very precise, I probably got them too hot or still dont have good joints on them. Sometimes the keyboard seems to hold a note. Not sure if that is a setting I accidentally turned on or some other thing I messed up lol. Its really cool that its at least making sound and responding to keys and pot adjustments now!
Edit: I also used a toothbrush and some isopropyl alcohol to clean all the excess flux on the solder side of the board!
That is good that it’s working now…at least somewhat.
The note staying on thing can happen when the keyboard doesn’t have a good ground reference. So make sure the power supply you are using is solid. It can also happen if one of the keyboard resistors isn’t soldered properly or has too much solder on its joints.
-BrachHey Brach! Good news, the synth seems to all be working properly. I reflashed the firmware to solve the notes sticking, I assume there was some corruption that occurred during the reflowing and volume pot shorting. Although everything is working, the synth seems overly quiet. I have to have the volume maxed out on the synth and still turn up my speaker system a considerable amount to really hear whats happening. Do you have any ideas on the cause of this and if there is anything that I can do to remedy the issue? Thanks in advance!
I’m glad to hear that it’s working well now.
As far as the volume issue…it could be anything in the analog circuit.
Are you able to hear sound from the on-board speaker?…is it very loud?
I couldn’t tell you specifically what the problem is. I know you were bridging some pins together on the volume pot. Make sure they are all soldered well. Check for other obvious things in that part of the circuit like solder joints. You could just re-flow all the joints in that part of the circuit to ensure they are all good. That’s all I know to say for now. I’m sorry that I can’t be more helpful in this case.
Good luck.
-Brach
