d8b mulfunction with youtube video

[muratasil]

hello again everyone,

I opened the board and contact cleaned all the ribbons,connectors,all the cards and card slots(one more time). I also tightened the BFC cable while connecting the cables, set and locked the apogee clock to 44.1, checked all bios settings. And you know what? I installed the OS and the plug-ins one more time for the hack of it !!! I even formatted the HD

Unfortunately I still have the sticky fader situation. It somehow behaved good after the OS install for 20 min. but then started sticking again. Something else I also noticed is that the metal base plate under the faders is extremely hot. I can't hold my palm on it for more than 15 secs. I'm not sure if it's related but I turned off the d8b to cool it for 5 min. and after booting up, it worked fine for 10 minutes. then the faders started sticking again... should I install a couple of big noiseless fans inside )) (bad joke, i know).
I think i tried everything that can be done from user-end. Still open to your suggestions, ideas etc.
the video below shows the sticky faders.(give it 10min. you tube is still processing it. EST11:16am)

Again, thnx for your support.

murat

some photos can be found here:
https://picasaweb.google.com/116281240914621089784/D8bProblems?authkey=Gv1sRgCJXg6PmP9b-TWw

[synthjoe]

Something else I also noticed is that the metal base plate under the faders is extremely hot. I can't hold my palm on it for more than 15 secs.

What about the control surface just below the faders, does it get equally hot?
The problem is, that motor drive is derived from 1. the current position (read out directly from the fader) and the 2. 'to be' value sent by the CPU - the differential signal as a function of these two is driving the motor. Since this second value is OK (the screen confirms this) and it is unlikely that all faders are intermittent the same way, the possible conclusions are:
1. fader position readout (A/D conversion), or 'to be' value D/A conversion (or both) are failing - this can be due to the inappropriate +5V supply regulated from the PC style PS 12V rail (anywhere down the line), or dying D/A and/or A/D converters (again, unlikely to happen on two banks of 8 faders the same way, the same time)
2. problem with the digital readout and/or sending of fader positions, which could be due to a problem with the serial port communications or the same between the fader board and the brain board (again, this latter is unlikely to hit both 8 fader banks the same way)

So my bet is still on serial communications (have you checked the serial cables INSIDE the CPU, too?), or the +12V supply.

One more thing would be a tell-tale: what about the working of V-pots and other switches, knobs? Are they working always fine, or failing similarly to the faders? No other ideas for the time being...

[muratasil]

Something else I also noticed is that the metal base plate under the faders is extremely hot. I can't hold my palm on it for more than 15 secs.

What about the control surface just below the faders, does it get equally hot?

just below the faders yes. what does this mean ??

[synthjoe]

Sorry, I've just edited my previous post while you were writing yours, please reread and would be interesting to know the anwer to those.

just below the faders yes. what does this mean ??

What I suspected: 'to be' and 'is' values are different and the motor is continuously driven, plus the 'on/off' does not work either - which is not a good thing. You shold not power on your desk for more than a few ten seconds, otherwise motors can burn out.
On/off, setting 'to be' value and readout all do not work - this seems to further confirm serial communications problems. If all other controls are dodgy, then serial comm between CPU and desk might be the culprit. However, I just recall that the 9 fader bank and master controls seemed to work, so (if just 2x8 faders are affected) it could be a problem between the brain board and the fader boards - you should check ribbon cables yet again. Otherwise, only some more in-depth analysis and measurements can shed sufficient light on what might be going on...

[muratasil]

synthjoe,

thank you.


here are my answers for both your posts:
1 - no i haven't checked the serial cables INSIDE the CPU. I'll check them as soon as i hit submit this post here. might be the problem you're right. I can check the +12V supply easily but if that's the problem switching with a new one is over my abilities. hope that's not the case.
2- V-pots, switches, knobs are fine both on the board and on the screen. so I assume there's no comm. problem there. the only faders that don't stick are 17-24 and the master. if it's a PSU related problem it should also have effected these, right ? please correct me if I'm wrong. more likely I am
3- F@*king ribbon cables !!! they all look in tip top shape from outside but who knows.But can 2 ribbon cables go bad at the same time ? unlikely... but anything is possible at this point right ? I'll recheck them also. Can it be the brain board ??? please not ~!~!~!~
4- i really don't know how much more in-depth analysis and measurements can you get in !
thanks for all the brain work and key strokes. I do appreciate it.


saga goes on !! girrrr....
murat

[muratasil]

I have just checked the SERIAL CABLE inside and it's ok. I also checked the new BNC cable. that's also ok ?? can it be the brain board ?????

[synthjoe]

I have just checked the SERIAL CABLE inside and it's ok. I also checked the new BNC cable. that's also ok ?? can it be the brain board ?????

Either that, or the cables connecting the two 8 fader banks to it. Really no specific idea what it might be, but gently tapping or flexing the brain board might yield some results... Or having a close look at it with a magnifying glass. My guess at this stage would be a bad solder joint, or something alike. Since the other controls are working fine and so is the 9 fader bank, I think we can safely exclude serial data comms issues and the PSU, too. Remains the brain board and the two fader bank PCBs.

Basically all communications with the brain board happens via pins 1, 3, 5, 7 and 9 of the ribbon cable (same on the 9 fader board) in a serial fashion, so if something goes wrong with any of these lines, then all faders in the bank will be affected. Other pins are carrying supply voltages. Actually, just as I wrote this I realized that attaching the 9 fader plug to one of the 8 fader brain board ports might reveal whether the port or the card is the faulty one. Just an idea to try, if you like...

[muratasil]

joe,

it's 4am here in istanbul and i was about to hit the sack. this is a great idea !!! i will switch the ports to see what will happen tomorrow morning.

I will let you know. thnx


best

[Crash]

I was gonna suggest something similar. If that doesn't work, just yank cable 38 and 39 and then see what happens... just for giggles.

I assume that when you reformatted the HD it wiped all the session files off the HD. So you are hopefully starting with a clean slate there....

[NigelC]

I know this might sound stupid but its also worth a go. I had an issue with sticking faders and it was caused by me accidentally blocking the path of a fader on start up one day. I recalibrated the faders (think its in the system menu) and it sorted it.

Also do you have the unit set to send and receive MIDI communications? I was experimenting with MIDI mapping once and found that if I had the wrong settings the DAW and the D8B fought each other for fader position creating some kind of MIDI feedback loop. As an experiment disconnect all external equipment from the D8B including your MOTU and see (apologies if you have already tried this).