m00dawg

Ooh that board looks really pretty for a protoboard nice job! Those heatsinks do look a tad small. My plan for my next power board is to use the heatsinks with the regulator standing up. They make ones that sort of wrap around the regulator that seem to work well. Having said that, I really like using my harvested heatsink from a motherboard. It's but can is able to cool both my regulators. You might look at going that way, but it does consume a fair bit of space. I was also thinking of trying some heatpipe stuff. If your case is metal you can try to use it to expel heat if the heatsinks themselves won't do. I dunno how well that would work but something to consider. I hadn't though of splitting 5V and 9V to improve noise. The transformers I have found seem rather large though so I don't know if that will work for me, but seems like a really good idea! Curious to see how things end up working out if you go that route!

In regards to a switching supply, I used to use one without issue and others on the forums have done so as well. However, you're dealing with an analog audio generator (the SID) so high frequency noise can be an issue. If you opt for a switching supply, I would still regulate it and add in plenty of filtering capacitors to smooth out and hopefully eliminate the HF noise. As for torids, I haven't tried these before because they are so goddamned expensive :) I bet they'll give you superior clean power but will you notice that from a noisy vintage analog audio chip? Probably not :) I'm sure there is plenty of room for debate about it. If cost weren't an object, I'd go for it, but I don't have any concrete evidence to prove one way or another if they will help.

Well yes that's important, but all you need to do is be mindful. Make sure to always check and have the power disconnected (from the wall) whenever working on the power supply. If you have to work on the PSU live (hint: don't) always use you right hand only and put your left hand in your pocket. That way, if you get zapped there's less chance it will, you know, do things like stop your heart. I put fuses on both the positive and neutral wires before the transformer (even have an extra fuse on the power plug if the others somehow fail). For me, I chose 1 amp fuses which seems to work well for preventing damage when I do something stupid that short something while I'm testing things with my multimeter. To prevent doing something stupid, I used the flat crimp connectors that fit the prongs on my transformer and my fuse holders to help prevent accidentally coming into contact with one of those guys (of course, if you follow the suggestions above, that would be a non-issue). After that, it's your typical power supply. Rectifier -> Capacitors -> Regulators -> Capacitors. The forum is full of information about how to build one of these and there is no shortage of design suggestions, so I'd do some searching if you're not sure how to proceed. As a hint, I tried doing crazy things with a center-tapped transformer. I'd recommend not trying to go that route and, instead, get a 9 or 12VAC transformer and regulate down to 9V, 5V, and 12V (if needed). In my case, I'm feeding each regulator directly from the transformer. You could stagger them (9V regulator's output is the input for the 5V regulator) but that seems like that would put a hefty load in the 9V regulator and it's not doing anything for heat - you still need to heatsink the things. I did that by grabbing a spare heatsink I harvested from a north bridge of a PC motherboard. Seems to work well, though for my final design I haven't decided what I should do. Making printed boards gets expensive and so I don't really want to waste space on a board to fit a huge heatsink. Either way, do be sure to heatsink the things. Have fun and good luck!

+1 for building a "real" power supply. Not only is it a fairly simple project which offers some nice learning opportunities, but you can build a linear (as opposed to switched) supply, which means it'll likely work better (and sound better). At some point I'm going to get a nice printed board for taking a 9VAC transformer and producing 9V and 5VDC. When I do, I'll be sure to post it. But you can make one fairly easily on a protoboard.

Haha yeah that's a problem. Been using my multimeter to the point I finally had to replace the battery :) The problem is I can't test it in the orientation the boards will be during normal use. So when I was testing it, it worked, but when I had the boards in their normal place, they didn't. Took me a while to figure out it was because of a bad connection. Kinda sucks but oh well :) The only thing I'm worried about is that it's going to look ghetto. If money and time grew on trees, I'd almost be inclined to start with a new board knowing what I now know :)

Yeah I ordered quite a few from him as well. They do work very good - I've even been able to use them for larger cable than its rated for (I used wires from a broken PSU for some of the power connections) without any problems.

Yep pre-bending is one of the steps I left out :/ I did have to resolder one of the cables. It wasn't terrible but was quite time consuming so if it's just like 3 or 4 bad contacts I'll likely go soldering a few wires. That will make it look ghetto but no one will see on the inside and I can fix it later (running out of time to finish it before I won't get a chance to work on it for a few months). The angled connectors would be a good idea but if I have to go to that much work, I'm wondering if it would be just as good to solder individual wires (which should bend a bit better). Still weighing my options...

I too was thinking the same thing about the corner holes. I wouldn't have minded them, but keep in mind that the corner holes aren't the only things supporting the panel. You should still use JB Weld to mount the hex bolts. You'll still need those to provide rigidity for the center parts of the panel. So, if you have to use JB Weld anyway, might as well make the panel look a bit nicer in the process :)

Yes, yes, I'm painfully reminded of that :) Although I do think these cables are a good solution. The problem is that I didn't do a very good job of putting the cables on correctly. I hadn't taken into account the stress. Actually, if the cables weren't quite so rigid it probably would not have been a big issue either. Oh well :) Far dig either way, although I still have the right angled connectors so I could still go that route. I'm going to look at it tomorrow and see how many bad connections there are. If it's not many, I'm going to go with the additional wire method. If that doesn't pan out, I'll probably re-evaluate.

Yep sure did! Turns out, though, that the root problem is the cabling I used. The cables themselves I think are sound (they are very similar to what you recommended on the Wiki and linked off one of the forum posts linked from it as well). However, I didn't hook the cables up flush to the board and I think over time the bending about broke some of the individual wires :( Still looking at my options. I'm thinking it might be easier to solder individual wires instead of cabling. That way if I do run into this problem again, I only need to replace the single wire instead of the entire cable. Only problem is that I have to unsolder all 8 cables (well, 7 maybe since I already swapped one and I think it's pretty solid). I suppose I could just solder additional wires on the contacts that are broken. Damnit :) Oh well. At least I nailed down the problem.

Aha! Let this be a word of warning to others! Turns out, the method I was using to test the connectivity of the cables didn't account for the orientation of the control surface. When I was testing it, the boards were folded, more or less, together. But when I actually supply power to the board, I stand the control surface up so it doesn't short out anything. In that orientation, there were shorts both with the 8th column and a few of the encoders (which explains why I was having issues in another post). Trouble is, I'm not sure how best to test things easily when in this mode but at least I know what the problem is. So, for anyone else building an MB-6582, be sure to take into account board positions when checking for continuity!

Well go figure now it only decrements :) I think the problem is likely something to do with the solder joins for the cables. I reflowed many joins that appeared to be in mediocre shape and the result is counting down instead of up. I will continue to play with it though since I think I've honed in on what the problem likely is. I went ahead and replaced the encoder (before reflowing the joins) and it still only counted up. So it doesn't appear to be that, though I did check for shorts under the knobs as suggested. I'll keep at it!

Well I was able to get things fixed. As best as I can tell it was a cold solder joint somewhere - it didn't seem to be in the cable though (I found quite a few bad solder joints for the cable connections, but this wasn't one of them). Nonetheless, I reflowed some solder and now it seems to be in good shape! You are a saint, Wilba!

Hahah mad props on the local electronics shop search :) I have been wanting to go there for quite some time. Trouble is, they aren't open on weekends so I've had a hard time getting there. If it is the transistor though, I can get it from Mouser or Allied Electronics within just a few days so it's not a huge deal. I tried some of the tests you described but didn't try to force the sink (should've thought of that :/) so I'll give that a go.

I tried searching around for this but I have a weird issue where one of the encoders on my MB6582 (center one on the top row) only seems to increment if I turn the knob left and right. I've checked the pins, traced back all the way to the IC and swapped chips. Same result. Seems like I probably need to replace the encoder but I thought I'd check to see if someone has seen this before?

Hmm...well I fixed the biggest problem, but now I have a column (column 8 on the matrix) that won't illuminate. I've pretty much ruled out everything but the transistor. I get continuity from the IC to the resistor, from the resistor to transistor. The transistor also appears to be properly grounded and the output to the CS works as well. If I tie the LEDs to ground, they light up. This column, I thought, was working yesterday so my thought is that something caused the transistor to go bad. Is there any way I can test this without unsoldering the thing and getting a new one (which unfortunately I do not have and will have to order - damn :/)?

AHA! I found the problem. It was that the capacitor for U21 was touching the track that went to pin 14 for U22 via a bad solder point. Fixed that and now the board lights up! I do have a few LEDs that aren't lighting up that I need to investigate but at least the damn thing lights up now, w00t! Thanks again for all your help Wilba!

Ah ok here's something interesting (maybe?). When I run the Serial Interconnection Test the data pints of U23 show up as -0.40V to ground whereas the data pins on U22 and U21 show up as 0 volts. I also noticed that the voltage from the SC and RC pins is slightly lower (4.94V) than testing the +5V on one of the CORE sockets (4.98V).

Ok so I ran +5V to pin 14 of U23 (with chip in) and pin 9 of U22. Both cause the matrix to light up as advertised...well, the 7th column didn't light up so that's an issue but I think I should worry about that later. So it looks like the shift register stuff is working. I'm going to go back and try the SRIO test again to see if I missed anything but other than that I'm still kinda at a loss...

Ah yes that's a very good idea! I think I'm going to reflow the solder on the sockets to be sure as well. If that doesn't work, I'll do this as the next step.

How unsafe can mounting things on cinder blocks be :) People build houses with it. At least you have it clamped down :) Anyways that case looks awesome! Boards fit really well too! My only recommendation is that having a clear box means you should mount some LEDs in there and make it glow :)

Ah good point. Yes I did get the right outputs, but one thing I didn't test for was if I was getting the wrong signals on the test, only the right ones. So I am likely going to rerun it and check all pins at each sequence of the test to make sure they are all what they should be. When you say check for continuity between the pins can you elaborate a bit? Having trouble producing a clear picture there. You mean the soldered pins on the bottom of the board? Re-soldering is a good idea. I did a few reflows on the resistors but didn't do anything on the socket so I'll go back and check again. Thanks for being so helpful and patient Wilba!

Looks like the transistors are working. I removed the chip and supplied 5V as suggested and it lit up the lines on the matrix. I ran through testing the IC socket and that, too, appears to be working. I tested continuity across the chain from the first to the last IC and it seems to be working correctly. The other pins are working as normal too it looks like (I'm getting +5 and GND where I should be, things like that). If the transistors and ICs work, though, it seems like it has to be something in the communication between ICs? I'll take another close look at the bottom of the board too just in case there is a short anywhere around the socket. I checked the transistors, resistors and cabling and didn't see one. I can try re-running some tests too just to make sure. As for the buttons, I assume you mean current sinking specific to DIN? The buttons do not relate in any way to the LEDs electrically do they? So close yet so far! Thanks again for all the help Wilba! Gave me some food for thought so we'll see what happens!

Sounds like it's a connection is my bet. I played swap the IC chips a few times already and re-ran the grounding test with the same results, so I don't think it's a bad IC (or doesn't seem to be). I believe I have some extra ICs I can try if I just want to eliminate the whole lot. I did check the socket but I didn't check the chaining or +5V all that much. I'll do that again and see what comes of it. I DID find a cold solder joint for one of the resistors on the 2nd IC though so I fixed that.

So after all my testing, I've determined that there is indeed something up with, most likely, the current sinking. Removing the '595 from the last socket and grounding those pins causes the matrix to light up (I was using the first LED test) on whichever pins were grounded. I've checked and rechecked the continuity and ran the SRIO tester. Everything appears to be as it should be. I also tried swapping chips but all the chips seem to work as they should. That leaves the transistors but I have a hard time believing they could be the cuplrit? They are installed the correct way according to the silkscreen (flat part to the right) and they pass a continuity test as well. Could one bad transistor mess up all the LEDs? I wouldn't have thought so? Can a short on the control surface possibly cause this? I haven't done an extensive test of the switches but the rotary encoders seem to be working at least. Hmmm...