d8b Forum

Yesterday in the middle of a mix, a loud hum from the speakers, then, pop, pop, pop etc, no audio.

Today I booted up, a loud hum from the speakers, VU's from the tracks but nothing on the master VU, switched off, tried again, Hum and rumbling from the speakers, no VU's then a message asking for V5.1 Authorisation code,

The only thing I've checked so far is the BIOS and that's ok, any ideas guys!!!

Phil

EDIT:- Just tried my other CPU and it's the same so it looks like it's the desk.
EDIT:- Opened desk, can't see any swallen or burnt caps? Doing a connector re-seat just to see?
EDIT:- Did a re-seat with everything, now, loud hum from speakers, no pops and rumbles, VU's show but not the master, transport works but nearfield & main volume stuck on full, EQ not really working, jittery, I also swapped the Line Control Surface board with no difference, so it looks like it's the brown square rail caps need changing, not sure where these are?

Ouch - doesn't sound good.
Can you give more specifics?
Are you able to boot up to the gui with a working mouse?
(that would mean the OS loads, and sends the firmware to the desk).
Does the desk respond to the booting, like showing "d8b" in the display?
(means it's recieving the firmware).

The desk boots as normal but with speaker hum and rumbling, v5.1 loads ok, I can load in a project, VU's show but no master VU. The speaker & Headphone volume knobs are jittery, so is eq as it's not possible to use it properly, the TV monitor image shows faders etc jittering.

Reading from the Data Bank, it sounds like Rail Caps, I have swapped the Line Control Surface board with another desk and it's not that, maybe the DSP board, I might swap that later?

Nothing wrong with the CPU as I've tried it with my other desk.

EDIT:- Just swapped the four boards, DSP, Analog, DCA and Codec and no difference!

Hmm...
Let me recap, to see if I got it right:
You can boot up fully with no errors/glitches on one desk.
With the other desk, it boots up to a working gui, but it jitters, and there's hum from the speakers.

Try reseating all cards on the backplane - particularly the clock card, digital out etc.
Inside - I think you mentioned checking the large caps on the power board with the BFC connector. If not, check that they're not bulging.
unplug and reseat the various cables inside the desk - particularly on the power board.

Hope it's not your rail caps - those buggers are tiny and difficult to work on.

To recap,

I have two d8b's and HDR's, I only use one D8b & one HDR this is the one that's got the problem, I have done everything, It's not the CPU, or PC Boards in the desk because I have swapped everything with my good D8b, the only thing I haven't tried is swapping the power boards, which is next on my list.

Power boards swapped, same problem?

erf.
Did you also try swapping the brain board?
Last thing to try before doing the cap job, would be to reinstall the OS.

Grasping... Trying to help

Word Clock! Funny things happen when it is not working.

I had a similar problem (not exactly the same) 2 months ago and it magically corrected it self. That's no help but that is what happened.

Bruce

Swapped the Brainboard, Just took out the two Surface Boards because there's a few connectors behind there that you can't get to, later I'm going to get the other Surface board (EQ) section out and the jog wheel.

Bruce, the Master Word Clock works with my other desk!

No cap problem because all boards work in a other desk?

This is a bit of a shot in the dark, and I think someone suggested this already, but I didn't see if you tried this:

Did you try removing all the cards from the card-cage in the back, just leaving the clock card in?

When I first got mine, one of my desks had all kinds of clocking issues (resulting in audio issues as well), and occasionally, the faders in the GUI on the monitor would also twitch around like crazy. I eventually figured out that it was the Tape 17-24 card SLOT (not the card in it, that one worked fine when used in another slot).

I tried cleaning it repeatedly and reseated the ribbon cables and cleaned the contacts repeatedly, but the problem stayed the same. Then I left the card out for some weeks and kept using the desk without it... and weeks later, I just put the card back in and the problems were gone. Not sure why.

Again... probably not the same thing, but sounds like you tried the usual suspects already, so it's probably time to try the long-shots...

The only other thing I can think of right now, is that some ribbon cables themselves might have developed issues. I think the connectors can also start having bad contact with the wires in the cables. It's possible to remove the connectors and clamp them back on in a new spot (if there's enough cable length available to do that... then you cut the excess cable that sticks out past the connector). But I'd only do this as a last-resort option... maybe only after opening both your desks and swapping the cables around, too, to pinpoint the issue.

I don't know... that's a tough issue, since you already tried all the stuff I'd also have tried first...

Best of luck!