d8b Forum

So started up my studio tonight with 2 d8bs. Everything was routine. Then working in cubase, could not figure out why I was not getting any audio output. Glanced over to my d8b and noticed that the desk was dead. No lights no vacuum display, nothing. But the monitor still shows mix window. Tried to reboot and still nothing, now I get reset error on Monitor. The CPU does boot up. Shut it down and rebooted a couple of minutes later turned on again. Now very dim blinking LEDs, only a few and fader board 1 keeps trying to to slam to zero db. I suspect the Aztec power supply, the one that powers the desk is shot. But reading I see that it might also be the Linear Power Supply.

Any ideas would be greatly appreciated.

Thanks.

RJ

Have you tried reseating the BFC connector?

Swap power supply/cpu and see if the issue follows to the other console. You will know where to start. Or, bust out the multimeter and start measuring pins on the big ass connector and see if you get what is supposed to be there.

Thanks for the Ideas. Tonight i will try 2 things to confirm. I have a spare desk so i will plug that in to the CPU and see if the problem persists. If it does, then that will point me to the CPU Power supply. That in itself will reset the BFC. I do notice that the CMOS battery in the CPU has died, but it died weeks ago as i was having to go into the bios settings and initialize before the OS would boot, however the desk at that point always had power. So if i confirm that the CPU power supply is shot, which is the one more likely to be the culprit, the Aztec power supply or the linear power supply?

Thanks

RJ

I can't remember which power supply does which voltages off the top of my head. Here is a service manual if that might help.

https://drive.google.com/file/d/0B2F66r ... sp=sharing

Well, all i can say is i am totally amazed and somewhat baffled. Tonight i replaced the desk with another desk that i have and to my surprise it booted up fine but obviously the DSN codes did not match so it stopped, but more importantly, it was alive. So just for kicks, i plugged the old one back in and it booted up with no problems. I am now conducting a heat test to see if it stays on. If it remains fine, then the problem had to be in the BFC, and i never thought for a minute that it would be that. Here is what stumps me. the BFC doesn't move ever. So why would it all of a sudden become a source of a problem.

My wife said i should chuck both of my d8b's and replace them. I said we did not have the money to replace them one of them let alone both. More so, i just realized how much i am in love with my d8b's. I never want them to die!! I will keep nursing them until i am too old too!! Why on earth did Mackie ever stop making them. In my opinion, the d8b was one of the best pieces of equipment ever made. AS I AM TYPING THIS, I GLANCED AT MY D8B AND AM WITNESSING IT SHUT DOWN AGAIN. OH NO! SO wondering now if it is a heat problem. Forget what i said about the BFC!

RJ

Okay so here is a quick up to the minute update. To determine if there is a heat problem with the desk, I quickly changed the desk while the CPU is still warm. The problem persists even with the desk that just worked about 5 minutes ago, That tells me the problem is not in the desk but in the power supply. Sounds like a capacitor but i am not sure. Any suggestions? I think the Linear Power supply is located in the desk so this leads me to the conclusion that the Aztec power supply inside the CPU is shot. Anyone concur?

Here is an update for everyone. I guess today i am just about the luckiest person around. I opened the CPU and note that both the Aztec power supply and the Linear Power supply are both there, so i was mistaken for thinking that the linear power supply was in the desk. I few years ago i purchased a whole box of spare parts for the d8b from a seller in the UK. I dug the box out and rummaged through it and found a linear power supply board. SO i went to work and performed surgery to replace it. Put it all back together and booted it up. It is working!! SO far on the heat test i think it has been about 10-15 minutes.

Very lucky...well done

Congrats on getting the issue fixed, all very good info for future reference should the same issue pop up for others, glad it wasn't an expensive fix just an unusual one.