Built a custom D8B external power supply

[RJH_MUSIC]

I have some partial good news to report. I originally suspected and still suspected the cable as being the root of the problem. I Hooked up all of the original d8b parts including all the power supplies, circuit boards and internal wiring. The only thing different is that I used a different bfc and still had to use butt splices because I had already cut the molex connectors off. On first start the console would jot come alive. Then I pulled the sense connection from the LPS-152 power supply and again the console came to life but no success with full boot. Now I switched out the LPS-152 5v supply with the new one I purchased with sense and connected it. This time the console not only came to life but it fully booted. I did not see the meters jump, but faders and pan pots fully work manually and using the mouse. This confirms my suspicion that there is something wrong with the bfc cable. Since it ohmed out correctly, I am still pointing toward cable length as being the problem. This is further supported by the fact by using the original LPS 152 5v power supply with sense connected, the console failed to start, but with new power suppy and sense, it worked. I think the reason the original would not work with sense has something to do with the buttons splices. Connecting I p the more powerful 5 v supply made it boot fully with shorter cable. I do remember in the first post in this thread that livefromheaven noted that the console was touchy and seemed to only work with the 5v adjusted to 5.38v. So the next step is to recreate that setting and hook up something to the console to see if I get audio.

When I extended the bfc cable, I used 2 sets of butt splices at either end of the extension because I had cut one end already when I built the first power supply. The key might be using a better method of joining the two pieces of the cable. Maybe using a metal sleeve and solder instead of a butt slice. I think this is down to solving 2 issues. The original cable length worked but the sense would not work on the original power supply because of the resistance from the butt slices. The second issue is even with newer power supply, there is a possibility that the extend cable length to 50 feet in addition to using butt splices caused the problem.

Off to build some new cable and Will, let you know how it rolls.

Rj

[RJH_MUSIC]

Pics of today

[Y-my-R]

You're probably aware, but Captain America on here, and myself are running 50 foot BFC cables between the console and the rack unit. However, they're both "original" as in from a proof-of-concept/pilot manufacturing run, and were never mass produced.

So, the over-all length doesn't seem to be the problem, IMO. I don't understand how the "sensing" connection works, but if it's not that, then I'd have to concur that it's probably something about how the cables got joined together.

[RJH_MUSIC]

Well after everything I've done today I'd have to say you are absolutely right. I have no explanation for what I'm about to tell everyone and I'm not sure I will ever figure it out and maybe it's just a ghost in the machine I don't know. So I mounted everything back in the new case which means I took the linear power supply board off its original chassie mount bout and put it in the cavity in my new case. Booted up the D8P and it would not come alive. Could not figure out what The problem was but I did discover that I damaged one of the rectifiers on the linear power supply board and now I had to unsodder it carefully and steal 1 from 1 of the vellman kits I bought. Got that fixed and it still wouldn't work. Took the linear power supply board out of where I located it put it back on the chassie mount from the original d8b booted up with the 50' cable and loan behold everything works everything works except the sense.

The only difference between the 2 mounts is the metal brace in the original d8b that hold the rectifiers to the mounting plate for heat dissipation. Maybe they were too hot without the brace and that prevented the unit from booting, or maybe the board flexed the way I had it mounted. So I just have to figure out how kit to cut the plate and mount in the box. Finally hitting pay dirt I hope. Also need to test the audio, because the meters still do not jump at the end of the bootup process.

I would love to get my hands on maybe 4 of those cables you mentioned. Can you share where you got them made? Or did you make them?

Thanks

RJ

[RJH_MUSIC]

Really post smaller pics

[Y-my-R]

Great to hear that it booted up! Sounds like now it'll be all about making it all work from within the same box (and with a longer cable)?

As mentioned, those BFC cables were from a proof-of-concept run or a pilot run. Not from mass production.
In case those terms aren't clear... a proof-of-concept build is usually a one-off hand-made unit, just to test/confirm that it actually works. A pilot run happens, when the proof of concept was successful. A pilot run usually is only to manufacture a small number of units (differs per product and company... but something like 10-50). This is usually to make sure what comes off the assembly line is ready to be sent to the stores. From the pilot run, there's usually a "golden unit" being picked, that all manufacturing units are being compared to, if they have any sort of imperfection... to make sure it looks at least as good as the golden unit. With the golden unit in place, mass production can start.

...but sometimes mass production does NOT start (like here). I assume that there was no business justification for it - meaning, they probably didn't expect to sell enough extended cables for this to be profitable.

So, the BFC cables Captain America and I have, are from either a proof-of-concept build, or a pilot run, not sure. These cables were never sold to the public, AFAIK... I just got lucky with mine, and lucky again that a Mackie employee still found one in his garage (that's Captain America's now).

Thinking that there might be more people who would have a use for those longer cables, I asked if there might be any more around, but there aren't (at least not at Mackie).
Next, I looked up the company name that's printed on the BFC cable, and contacted them. They also have none left, but they said they could make some with permission from Mackie. I got permission from Mackie (Loud Technologies, actually).

Then I checked with the manufacturer of the cable again, and to meet their minimum purchase quantity to start a manufacturing run, at least 20 people would have had to confirm ahead of time, that they'd take a cable like that for around $200-$250 (if I remember right). NOBODY reacted. So, the whole thing stopped there.

If you could find around 20 people (or 16 more, if you need 4 long cables yourself) to get the funds together for a production run to make sense, then you could have the cables with about a month of turnaround time (if I remember right). The manufacturer will NOT guarantee that these will work for the intended purpose... they'll just guarantee that they're to the same specs as the original cable they made by Mackie.

Here's the thread where all of this went down...
viewtopic.php?f=2&t=2389&p=17743&hilit=kemcor#p17743

[RJH_MUSIC]

Thanks much, and thanks for the edu-ma-cation. I think I am going to try removing the butt splices and trying solder sleeves instead to see if that helps.

Sense is working using the new 5v power supply. Full boot but no audio. Can someone confirm that on the Linear Power Board the is thermal tape between +/- 16 rectifiers metal tab and the chassie plate. I did not think I should see continuity there, but with the molex connectors attached, I am.

[RJH_MUSIC]

Man this just keeps getting more weird by the minute. Took a working unit (remote and console) and hooked up my home-made cable to it and it worked fully. I then hooked my good CPU to the console I have been testing with the new CPU and it would not boot up. This leads me to believe I somehow damaged the Console. Then I tried to boot the good console using the new power supply and it would not boot up until I disconnected the sense output, and when it did, no audio. This leads me to believe that in addition to damaging the test console, I must have damaged the linear power supply board in the new CPU. So the only thing I have confirmed is that the home-made cable is good.

Any ideas of what to check in the console that might have blown??

RJ

[RJH_MUSIC]

Also, did this using all original d8b power supplies. I guess the next thing to try is repeating this test with a spare LPS-152 5v supply to see if there is a difference.

RJ

[RJH_MUSIC]

So last night I did some testing with known good consoles and I found out that the stupid LPS 152 power supply was causing the trouble with being able to boot up. So I replaced the LPS 152 power supply and now my original working console boots using the new cable. So there is nothing wrong with cable. Both linear power supply boards are good as well. I am left with trying to figure out what I damaged in the console I was using to test new power supply. It still boots up fully but no meter Flash during bootup and no audio. I took the bottom off and I do not see any visible burn marks anywhere. Since everything else works except audio, I am leaning toward looking closely at the ÷/- 16 circuits. Maybe I shorted something.

Anybody have any ideas of what to check?. I am reluctant to proceed with new power supply cpu until I find out what happened. Could it be that not properly isolating the rectifiers on the Linear power supply board originally shorted something. ?