power distribution board

[flipflop]

Hi all..
It's been awhile since I looked at the site. I lost my digital board last year but managed to find someone who knows a little bit about electronics. He is telling me to replace the power distribution board which may fix my DSP error. Any thoughts on this and / or is this part findable. I'm waiting to take the next step so any response would be appreciated.
Phil.

[csp]

Phil,

1. I would need to ask what you mean by "I lost my digital board last year" , because if you actually lost/misplaced the desk (I presume that is what you mean by "digital board") how can you repair it !!!!

2. Asuming that you are referring to a d8b desk, we would need to know why the electronics person is saying that you should replace the "power distribution board".

3. Exactly what do you mean by the "DSP Error", is it an error message on the external monitor or the desk's VDU and if so what is the exact message, or is it something else that leads you to believe that there is possibly a fault with DSP Board.

4. Have you undertaken a full and complete clean of the ribbon cables and their associated PC sockets, including a full continuity check of every lead in every ribbon cable --- you should be getting no more than 1 or 2 ohms resistance between the ends of each individual wire. Not sure where you are located but if in the USA then most of the d8b users recommend using Deoxit.

Hope all of the above helps a bit.

David

[flipflop]

Wow... you are right David. I didn't explain the order of my actions. This does pertain to the Mackie d8b 56 input / 72 output digital mixer. With a RME Hammerfall DSP system used in Windows 10. Board went funky in 2020

1) I sent the CPU out for repairs as it had a defective 5v power supply. The technician replaced that with his version of a power supply which worked. Note: Two small wires off the large power supply board were not attached to the new supply.
????

2) I removed and cleaned as much as I dared, all circuit boards, and recrimped all ribbon cables that I could access. Note: The desk VDU has never worked since I purchased it. (never found it a problem) ???

3) Successfully transferred the operating system to an ssd card, boot up still had problems. DSP error on monitor.

4) Sent console and CPU to a new technician. His diagnostic was that there is no ground on some of the pins from the BFC cable, so, he's suggesting that I swap out the power supply board where the BFC plugs in to see if makes a difference.

With all this, I've also changed the apogee clock and two slider boards. Sometimes it will boot up but there is little or no communication with the sound or any control of the console. I would really like to repair my board so if you have any more suggestions I would be glad to humor them.

Phil.

[csp]

Phil,

I can be of zero assistance in relation to the Hammerfall system and if it could be effecting the desk's operation, others might be able to assist with that.

1. Again not knowing what the technician did or swapped I can be of very little help, however if there were two wires that were not connected that could be causing a major problem. Just a shame that he did not repair the 5V fault on the original power supply, because then you would know that all was as it should be. The d8b is apparently very finicky to modifications.

2. After the cleaning of the ribbon cables did you happen to do a full continuity check from end to end of each individual wire in each ribbon cable --- a tedious job but one well worth doing ---, because even with a clean, etc there could still be a faulty connection in one or more of the wires. It would be interesting to know why the VDU has not worked, because this could point to another problem that is now causing major problems. I have not heard of a desk where the VDU was not working.

3. The DSP error could indicate a number of problems including clock problems. It you have the bottom off the desk, it would be interesting to know what the three LEDS on the DSP board are showing as and after the desk goes through the booting process. Although there is virtually no information on these LEDs, for the DSP card to be working correctly the Red LED must be lit (some boards will display the Red and Green LEDs but the Red LED must be showing) --- any other situation and there will be no audio.

4. Are you saying that the second technician found the problem by removing the BFC from the back of the desk and then doing a continuity check from the actual BFC multi pin plug back to inside the Rack Unit or did he simply connect the BCF plug to the desk and read some form of continuity between the Rack Unit and the desk side of the plug where it connects to the PC power distribution board inside the desk. OR did he simply check for continuity from the socket side of the BFC connector on the back of the desk and the appropriate connections on the desk side of the Power Distribution PC board.

5. Your last paragraph, have you undertaken a continuity check of the data cable from end to end and is it VERY firmly connected at both ends and have the sockets been cleaned on the desk and Rack Unit ends. A fault connection or problem with this cable and its associated electronics will definitely cause DSP board problems.

I realise that the foregoing raises lots of questions and very few (if any) real answers, but hopefully it might give you somethings to eitherr work on or think about and hopefully others might join in and give some more positive ideas/suggestions.

David

[flipflop]

Thanks David
This will be quite the undertaking so you probably won't hear from me till the new year. Wish me luck and have a safe and happy holiday...
Phil

[csp]

Phil,

OK and likewise have a great Festive Season and all the best with trying to get the desk to work.

If you really get borde over the vacation period you might like to read the topic I started about 19mths ago titled "Not Quite The End Of The Saga" as in its 50 odd pages of information I think that every possible problem and combination of problems that could happen with a d8b has been discovered and discussed and you might possibly find some ideas that you had not thought about.

David