Built a custom D8B external power supply

[RJH_MUSIC]

lol - sounds like good news. Thanks. I powered up the desk last night and it worked, so now i will connect the CPU and power that up an keep my fingers crossed. Also, testing on an older console, not my current d8b, so if it blows up, that it is a lesson learned and won't damage my working unit.

[RJH_MUSIC]

I am very sad to report that my experiment has hit a major snag. Hooked up the new power supply and the old CPU and successfully booted to mixer screen at which point i was greeted by the prompt to enter my Authorization #. This should not have happened because this is an original unit with auth # intact, so that tells me the Brain board is not working correctly, and that is the board that used +/- 16 VDC. I hope i did not damage the brain board. Second problem, jumping and dancing pots, and faders not working properly. Tweaked the +5 to about 5.5 and some went away but still present.

I guess were i am confused is that following other posts here and using same parts, cannot understand why this is not working. Would really appreciate someone who has done this successfully to give me some insight. My only choice is to scrap the project and but a complete new d8b to replace the one I have.

[doktor1360]

I am very sad to report that my experiment has hit a major snag. Hooked up the new power supply and the old CPU and successfully booted to mixer screen at which point i was greeted by the prompt to enter my Authorization #. This should not have happened because this is an original unit with auth # intact, so that tells me the Brain board is not working correctly, and that is the board that used +/- 16 VDC. I hope i did not damage the brain board. Second problem, jumping and dancing pots, and faders not working properly. Tweaked the +5 to about 5.5 and some went away but still present.

I guess were i am confused is that following other posts here and using same parts, cannot understand why this is not working. Would really appreciate someone who has done this successfully to give me some insight. My only choice is to scrap the project and but a complete new d8b to replace the one I have.

Dunno, might be that the Brain Board is just sensitive to the (+/-)16VDC supply - and you could have been correct all along, and that the voltages really are expected to be at a (+/-)16VDC minimum or thereabouts. It would be similar to putting (+/-)5VDC, it would most likely power up the ttl logic ic's but anything requiring the 16VDC is probably gonna be wonky at best - the fact that the console is responding is encouraging, tho. Perhaps some sort of 'read' operation failing?!? If only you could get a few answers from the poster you've quoted that's already accomplished all this, that would certainly help mitigate some of this uncertainty. I personally believe you've just hit a snafu of sorts, voltages can be a real PITA when you don't have the engineering spec sitting in front of ya for voltage test points and/or 'stare and compare' debugging...

[RJH_MUSIC]

I tried to send a PM to the members that posted the original material, but got a reply from the forum that there were no such members in the database. Well after doing some soul searching i think i finally understand the term that was mentioned in the original post link instructions which refers to a "Velleman" kit. I looked up step-up transformers on the internet and was directed to a page that sells these kits.They step up the voltage for the +/- 16 VDC. I have another option, which i like better but it is more involved. I originally was going to use a 1 RU case for the power supply and a 2 RU separate case for the CPU. I bought a 50 foot Data Cable so i could place the acutal CPU further away from the console to elliminate fan noise in the audio circuits, but i did not want to mess with trying to change the length of the BFC cable. SInce i went ahead and cut all the wires anway, i am now going to look at mounting everything in a 2 RU case with adequate colling fans, use the original parts from the remote and just replace the 5 VDC power supply which is the one that always goes bad. That would actually be a better scenario because in the end i would have a 2 RU CPU instead of a 2 plus 1 more.

[Y-my-R]

I understand that the brain board is what would respond with the correct auth code the OS had been authorized with, and that it's likely that this symptom is pointing to the brain board not working correctly...

...but people seem to have issues where the authorization just gets lost and they keep getting prompted for the auth codes, even on units that were previously successfully authorized, no hardware changed, the brain board works, and they STILL get an auth code prompt, sometimes.

Because of that... what about applying the crack to that OS drive, or using another drive that has the crack applied, already, to be sure that it isn't really just an authorization problem...? (...as long as booting the unit without the voltage being properly regulated for the brain board via that velman kit/step up/down transformer won't cause damage).

...just thinking out loud. At least using a drive with the crack would eliminate an actual auth issue from being a possible cause for this error message.

[doktor1360]

Sounds sensible, and indicates the D8B circuitry most likely requires a (+/-)16VDC minimum for operation, with a (most likely) 10% over-voltage tolerance. In this case, if you're using said 'Velleman' kit to pull the voltages up (more negative), it's doubtful you'd ever approach and develop an actual over-voltage use case. That would, I think, allow everything on that voltage rail to operate properly to spec. Problem solved... onto the next one (LOL)...

Pretty damn slick, what you're doing tho... all the best in your endeavors, and keep on posting the progress. I'd love to see ya get to your desired end result... kudos!

And again, as always, this has to be stated due to the speculative nature of the some of the conversation:
[Standard Mgmt Disclaimer] - "Your actual mileage may vary..."

[RJH_MUSIC]

Great suggestions. I did try a flash card with hack and still got authorization request, so I do think the problem is with the voltage on the ÷/- 16. My problem is I am not an engineer, so I do not know enough to figure out what type of vellum. Kit I need. I wish the instructions posted in the forum were more clear. The good news is it doesn't sound like I ruined anything.

Thanks for all the support. I will keep you all posted.

[RJH_MUSIC]

So doing some more research on this, it appears I missed an important step. First, looking at the d8b schematics, I can now understand why the faders were all messed up. All of the fader boards are connected to the Brain board which is mainly governed by the +/- 16 VDC. What I do not understand is the jumpy pots, because they are mostly governed by the +5 VDC. Further, I found a Velleman kit that can convert both the +/- outputs between 1.2 - 24 VDC. So I think I was supposed to construct the velleman kit and connect the Traco +/- 15 VDC power supply to its input and then adjust both outputs to +16 and -16 respectively. My problem is that I do not have any more room inside the 1 RU case unless I remove the +48 VDC and forgo the phantom power.

So I will now turn to plan 2, which is to use the larger 2 RU case to house everything and forego splitting the CPU from the PSU. I has way beefier fans for cooling so I think it will be okay. And since it is only 2 RU if it works, I will wind up reducing the original 3 RU unit to 2 RU. Win Win!

[RJH_MUSIC]

SO I had another major setback last night, but I am even more determined now to see this through. I decided to shift gears and build up a 2 RU combined CPU and PSU in one case. Reason being because if I have to build up Velleman kit to convert the +/- 15 VDC to +/- 16 VDC, I have no more room in the 1 RU case to do that. I successfully mounted the motherboard, Floppy disk, Flash Card computer power supply and fuse board from the original d8b into the 2 RU case. Doing a small test with just a monitor connected to see if it would boot up, the low profile VGA card I used would not drive video. The good news is that at least it powered up and the fans are super quiet. Rather than buy up every VGA card available on the net to find one that will work, (Low Profile). I purchased a riser card on e-bay yesterday that will plug into the PCI slot with a ribbon cable on it that will provide 2 PCI ports to mount cards sideways so I can use the original ATI video card and it will fit in the 2RU case. So if I can solve that problem the only other problem to solve is finding out what type of Velleman kit to build. I found one online that is a dual input / output adjustable power supply that will allow me to input both + and - 15 VDC and separately adjust each output to up to +/- 24 VDC. I just don't know if the output amps are enough, but for $12.00 it can't hurt to try. As a last ditch effort, if nothing winds up working, I have enough room in the 2 RU case to mount all of the original CPU remote components into it. Which will effectively at least let me reduce the footprint from 3 RU to 2 RU with a lot more and quieter cooling.

Stay Tined - I will post pictures and instructions as I move forward.

[RJH_MUSIC]

Check out the pics posted to the thread related to new operating system.