Deckards Dream General Build Thread

[sduck]

Maybe that cap was soldered in the wrong way?

[LED-man]

2Amps is fine for testing with 1-2voices but not with all voices, there’s a current peak when the device is powered on. Furthermore it’s better to test the device without Voicecards for the first tests and for the flashing process.
It’s better to use a bench psu with current limiting for testing, a bench psu helps you to identify shorts/mistakes.

[c0ntr4d1ct10n]

Just built my DD rev2 motherboard, hardward board, psu, output board and a single voice card.
I want to test it without any chips first so I don't fry them just in case there is a short somewhere. Tested the power board by itself and it works, but when I plug it into the motherboard, the -5V and -12V flash slowly - is this normal?

[LED-man]

Not really good.
It’s a short in the circuit or less/wrong input power from the external psu.

[c0ntr4d1ct10n]

thanks, seems like the problem might related to a short on the hardware board between 3.3v and gnd. Maybe to do with the oled? I'm sure ive bought the right screen with the vcc as the first pin. But is the oled supposed to be upside down on the board?

[synthnl]

Does someone have some kind of test procedure? I got myself a bench PSU to start with.

[c0ntr4d1ct10n]

So I've managed to resolve the short circuit. Luckily I havent placed any of the chips in yet (lesson learnt from previous projects). I'd like to test the oled screen with the minimum - I got every component on the main board and hardware board soldered except for the slide pots and all the chip sockets are empty. I'm wondering which chips I would have to place to get just the oled showing something on the screen?

[Blue Meanie]

Funny that this guy said, "without opening mine up" after he mentioned he learned about the C3 bug on this forum.

[LED-man]

Pando is that „guy“, it was discussed on page 43.

[Blue Meanie]

Pando is that „guy“, it was discussed on page 43.

Oh, nice to know.

In the future, please don't take 3 months until you report a bug on the guide website. I'm sure other builders would appreciate it. Thanks!

[JanneI]

In the future, please don't take 3 months until you report a bug on the guide website. I'm sure other builders would appreciate it. Thanks!

Are you aware of the fact that LED-man's (Patrick's) website is NOT the official guide from Black Corporation? It's linked only because it's the best unofficial guide. The real question is why there's no official guide and that's a question towards to Black Corporation.

[Blue Meanie]

Yes, I'm aware there isn't a build guide provided by Black Corporation. I assumed C3 was a known bug after some snarky comment about ESD bags. Now I know the dude was just being crass, which is weird if they are the care-taker of a website dedicated to helping people with complex builds. 

No worries, bro.

[LED-man]

It would be easier with more people who edit my pages.
I’ll give edit permissions on request.

[Zifor]

Hi folks ,
I have built my deckards V1 and tested it. Everything works aside from one thing, one of my voice cards has a very audible click or pop whenever it is engaged ( adsr level does not affect this. No other voice does this regardless of Adsr levels. It almost sounds like a kick drum. What could be the problem? I am completely stumped and tried most obvious things. Any suggestions are welcome

[Chrutil]

So it is always the same voice?
Did you try moving the voice card around to verify if it is the actual voice card or the location?

[Zifor]

So it is always the same voice?
Did you try moving the voice card around to verify if it is the actual voice card or the location?

Yes only one voice. I moved it around and also soloed it. It’s definitely just one

[whyfarer]

Hi folks ,
I have built my deckards V1 and tested it. Everything works aside from one thing, one of my voice cards has a very audible click or pop whenever it is engaged ( adsr level does not affect this. No other voice does this regardless of Adsr levels. It almost sounds like a kick drum. What could be the problem? I am completely stumped and tried most obvious things. Any suggestions are welcome

I had this exact problem. I stuck that voice as my eighth and only played with 7 for a year. I didn't want to debug after the long build and 7 was enough... A few months ago I decided to solve it. I touched up all my SMD caps on the touchy voice, and then I took out all the voice cards except the bad one and one good one. I marked all the ICs on the bad one with a silver marking, and then I started doing a binary search for the bad chip. My plan was to swap all the the ICs and then to test both voices to see if it was any of the ICs. if not, that would eliminate a lot of possible problems and maybe point me to somewhere else to check. If the "good board" started popping after I swapped all the ICs, then it is one or more of the ICs that were the issue. I would then swap half the chips from good to bad and test both, then half the remaining ones, etc until I identified the bad ICs. But, after I swapped all the ICs.... both worked... So between touching up the little caps and reseating ICs I seem to have solved the issue. Long story on how I attempted to debug. Sorry I can't tell you what actually fixed my issue but I hope it helps.

[Zifor]

Hi folks ,
I have built my deckards V1 and tested it. Everything works aside from one thing, one of my voice cards has a very audible click or pop whenever it is engaged ( adsr level does not affect this. No other voice does this regardless of Adsr levels. It almost sounds like a kick drum. What could be the problem? I am completely stumped and tried most obvious things. Any suggestions are welcome

I had this exact problem. I stuck that voice as my eighth and only played with 7 for a year. I didn't want to debug after the long build and 7 was enough... A few months ago I decided to solve it. I touched up all my SMD caps on the touchy voice, and then I took out all the voice cards except the bad one and one good one. I marked all the ICs on the bad one with a silver marking, and then I started doing a binary search for the bad chip. My plan was to swap all the the ICs and then to test both voices to see if it was any of the ICs. if not, that would eliminate a lot of possible problems and maybe point me to somewhere else to check. If the "good board" started popping after I swapped all the ICs, then it is one or more of the ICs that were the issue. I would then swap half the chips from good to bad and test both, then half the remaining ones, etc until I identified the bad ICs. But, after I swapped all the ICs.... both worked... So between touching up the little caps and reseating ICs I seem to have solved the issue. Long story on how I attempted to debug. Sorry I can't tell you what actually fixed my issue but I hope it helps.

Thanks ! It shouldn’t be the decoupling caps but I’ll definitely check the ICs again

[Pando]

Funny that this guy said, "without opening mine up" after he mentioned he learned about the C3 bug on this forum.

Yes, I used a photo of the PCB to confirm the traces instead of opening up my unit and checking that one. Same thing. What's funny about it?

[Zifor]

I’ve tracked my problem down to VCO A. I am now trying to work our where that is on the voice card.

[Zifor]

I’ve tracked my problem down to VCO A. I am now trying to work our where that is on the voice card.

Mystery solved. Gave it a reflow and it did the trick. Thanks everyone!

[Blue Meanie]

Funny that this guy said, "without opening mine up" after he mentioned he learned about the C3 bug on this forum.

Yes, I used a photo of the PCB to confirm the traces instead of opening up my unit and checking that one. Same thing. What's funny about it?

My mistake, and nice catch on finding C3 is reversed.

[steviet]

I finally finished the SMD on the voice boards, quite the slog, but a beautiful slog.

I started creeping around looking at the rest of the SMD work, and I noticed there was a component missing on the PSU board. It doesn't look like it was ripped off, so I'm assuming it was left out for a reason. Here's a hot shot:



I googled around and searched the thread, can't seem to spot anyone mentioning it which worries me... Did I miss it? It's a REV2.1 PCB kit.

[c0ntr4d1ct10n]

Thanks LED-man! I know (would know) now how to continue. I don't have a bench power supply, however.

It looks like I have a problem. I'm really careful here, with soldering, double checking all components and their orientation, etc. The PSU board alone does deliver the right voltages. After connecting the system without voice cards, not much happened (of course). That the display stays black I assume is normal, I'd first need to install the bootloader I guess. But then I noticed that the R-78E5.0 on the PSU board got very hot. So I immediately unplugged power.

Trying to find out if there is any short, I have been measuring over each SMD capacitor on the main board (after removing all ICs from their sockets). I measured about just 9 ohms between +5 and ground of the pentanoise IC. So I've desoldered that SMD cap to see if it's defect, but after I still measure the same on the board. Now I'm also measuring about 8 to 9 ohms over all 12 SMD caps that are more or less behind the 12 MAX5* DACs. Can this be? Would they all be "blown"? Across all other SMD caps I don't measure any short. Basically I measure a short between ground and the +5V pins 31/32 of the power slot (not to the other +5V pins 13-16).

Another thing is that I don't measure a connection between the +3.3V on the PSU connector and pin 1 of the PBD1 connector to the hardware board. How can that be? The connection is there to the other PDB2 connector.

I'd appreciate if anyone could give me some more tips on debugging. It's difficult to find out between which pins of the DACs exactly the mentioned SMD caps are connected. According to the schematics there are multiple per DAC. If there was a short already, could the DACs break from that? The electrolytic C2 (between the affected +5V and ground) is correctly oriented. Should I desolder to see if it's defect? What more could cause this short?

It might not be a disaster if I would need to replace all DACs, but that's not going to be easy. I do hope there's something else to be fixed.

Thanks!
Peter

Hello, I'm having the same problem with the connection between the +3.3V on the PSU connector and pin 1 of the PBD1 - its measuring about 3.2kohms. I don't have any of the other problems you've mentioned though. Did you ever end up resolving this issue and do you know what caused it?

[c0ntr4d1ct10n]

Silly me. Turns out that this is normal as the 3.3v for the sliders is on a different rail on rev2.

So now I got the firmware loaded and the OLED is working. When I enter in a voice card (just a single one), the +5V led is off and -5V and -12V leds on the psu flash slowly meaning there must be some sort of error on the voice card right? Note that this still occurs even when I take out all of the chips on the voice card.

When I take out the voice card, the DD seems to boot fine and I get the main menu on the OLED. However, now none of the pushbuttons seem to work. Even the shift button doesn't seem to work (like before I loaded the firmware, I was able to turn it on while pressing shift, but now it doesn't seem to do anything).