Hi guys,
I got the same problems with my desk. After a lot of searching and testing I can confirm all of the mentioned symptoms.
My PSUs located in the CPU are all fine, delivering +16V, -16V, +48V, +5V; I also get these voltages in the desk itself, all the fuses are fine (between FB8 and FB10 and so on). I checked a lot of voltages that are mentioned in the schematics and they all seem fine (+/-5% at least, I hope that's ok).
Just now I even soldered a cable between MGND and DGND as mentioned in other posts. Still no improvement on the situation.
The only thing I couldn't check was the 5V_REG on control board (IC 7805 U1 Pin 3). Which control board is this? Based on searches in the service manual and in the schematics I figured this should be 120a (control surface board) because that's the only one designating a 7805 by U1. How do I get to this board with the console running? It's above (or with the desk downwards facing below) the brainboard, covered by the big strut sheet holding the brain board. Do you have any tips on how to get to this board without fully disassembling the insides and having flying wires and a second person holding the brainboard with everything connected to not short anything?
thanks for your help!
munkustrap wrote:@p2h
you do not have to re-order. let me know when you want to have the probox.
I think the probox will not fix your Problems as the vpots do not react but Buttons are ok.
you will have the same issue on the probox. We Need to fix that first
regarding your problems, let me repeat it quick.
- Switches and Switch LEDS are working and react (good, Firmware works, communication works)
- vpost do not react. I think the leds work when you do it with the mouse but it don't when you trun the vpot
- faders dont move. you said, that you have the Feeling that the faders sometimes want to go more down. Do they move down when you place them in the middle before powering up the whole console?
- meterbride dont work (ist this true)?
- check VPOT Channel 1, VPOT Channel 13 and VPOT Speaker Volume. are all 3 not working when you turn them?
- i think your controlroom should work (Audio) when you control the vpot with mouse (if you can) please check that. Ist necessary to check if +16/-16V supply Domain is ok.
I had a look into the schematics.
I think you have a Problem with the 12V supply or the components that gets 5V out of tese 12V
- check DGND,AGND and MGND is connected !!!
here measure on the power distribution board (d8b console with the big round connector ) if you have contact (0 ohm) between J101 and J201 (do this with the CPU/PSU connected to the d8b console but everything powered OFF)
- check in the PSU/CPU the fuse for 12V
- check in the PSU/CPU the 12V connector (squared White connector with two yellow and two violett/purple cables
- check the connector from CPU powersupply to the power board (4 pol connector White with 2xblack/yellow/red cable)
- check your 12V supply with a scope or multimeter in the d8b console !
- if this is all OK check 5V_REG on control board (IC 7805 U1 Pin 3. If you do not have this the vopts do not work
let me know the outcome
Posted: Thu Oct 09, 2014 4:42 pm