D&R dayner mixing desk problems! looking for help!

Hey Guys,

Love the forum. I plan to put a few GSSL compressors together.

Right now i have a D&R dayner mixing desk that has died on me... Well i think the power supply has died on me.

I've been fiddling with it for a while now but have no idea what i'm doing ???

I was wondering if someone is willing to take a loot at the power supply schematics and the master module schematics and try help me out???

Here is the schematics in PDF format

http://www.d-r.nl/dnrsite/Service%20Parts/DaynerServiceManual.pdf

All i know is that r302 in the master module burns out when i turn on the power supply and that the LED for the phantom power well stay on even if it's fuse is out. I have a feeling that the problem is my power supply but i don't know where to stick my multimeter to test everything.

Oh if anyone in Melbourne, Australia can fix it i'll give them some free recording time ;D

Cheers

Chris

Which fuse is out fro the +48V? I only see fuses for each of the main supplies (+/-V) and the primary of the transformer (P59).

Check C304 and C305 for short-circuit, also IC5 (U267 LED bar driver). R302 is a 100R resistor feeding this driver from the +17V rail. Looks like there is a short circuit on the IC side of the resistor. Measure with an ohmmeter when R302 is out and it will probably be very low.

Thanks for your response i'll check all that today.

The fuse is a 1A fuse.

I think there is a problem with both the + and - Rail...

I think that the -rail is not supply the power it should be. What Voltage and Amps should i be reading and where should i be checking it across?

There does not appear to be a separate fuse for the +48V supply, according to the schematic.

From your comments it appears you have very little knowledge of what you are doing. If you want to attempt to perform this repair yourself then you need to be aware that there is main voltage inside the unit which is lethal. Also there is a possibility that by attempting to fix it without understanding how to may result in the unit being damaged or destroyed.

If the resistor is burning up then that is an indication that the PSU is supplying something. There may be a problem with the devices being supplied (the LED driver for example). First step is to verify that the PSU is working in isolation from the rest of the circuit.

Disconnect the PSU output from everything and use a meter to check the suuply rails. It looks like the +/- rails are 17V. Check the +48V rail as well at the same time.

Switch your meter to AC and check the +/- rails for any ripple on them. With no load this should be very small. If there is a signnificant amount then the PSU caps may be high ESR. If you have an ESR meter you can test them, otherwise make a note to replace them at some stage.

Is it possible to power up each channel separateley (one at a time)? This will help isolate faults in each of the channels as they are brought up. There would appear to be a fault on the module with the burnt resistor anyway, so that would need to be fixed before re-attaching it. It will be more than the resistor. Something has caused the problem and I suspect the LED driver has gone S/C. This may have been caused by a PSU fault. If the PSU rails are above about 18VDC then it's likely that most of the op-amp IC's are dead also.

Do the PSU checks and return with some numbers.

I owned a D&R 8000 years before... the psu looks similar to the one which was used in my desk.
I would do nearly the same what gswan says...

You should remove all channels from the desk. (if you're not that experienced with electronics you will not damage all channels at once if the power supply has a problem... and gives too much voltage)
Then try to repair the PSU. If the psu is ok... reconnect every channel - step by step. Switch off the console when conencting a channel! Check if the LEDs on the psu are ok every time. Be very very careful with the conenctors at the channels. D&R used connectors which can easily cause big problems! It possible to plug in the connector so that every pin is at the wrong position... pin 1 is at pin 2, pin 2 is at pin 3... and so on. Your psu will probably be defective then, too. I once blowed my psu up this way, too. (one 2N3055 was defective after that) I checked twice - but not good enough.  ;D

Its probably a 3055 Transistor, or a 723 voltage regulator IC.
I had a problem with an IC in the master section, too. I changed the IC. But the silk screening was wrong... it showed a wrong orientation of the IC. So the polarity was interchanged. After that the psu was dead. One of the 2N3055 transistors was dead. I replaced the 2N3055 and it worked fine. THe 2N3055 is probably on the outside of the psu.. on heat sinks.
Either ask someone who is experienced with electronics... and he will fix it in 15 minutes... or try it yourselfs - if you want. (I woulnd't if I were you)  ;D

Otherwise:
Buy some 2N3055, 723 regulators and heat-conductive-paste and mica-sheets for 3055 transistors. Change all parts in the psu.

Be careful changing the 2N3055:
Probably the transistors are isolated with the heat sinks... thats why there is something between the transistor and heat sinks to avoid a connection. If there are plastic sheets between the transistor and the heatsinks... replace them! Or use the old ones. But don't forget them! Otherwise you and your PSU will explode.  (more or less) It will not work without these mica-sheets. (I don't know if its called mica-sheet? Thats what the translater says)
Be sure to use some heat-conductive-paste for the transistors... look where the paste was when you removed the transistor.

Be careful changing the 723:
Do not bend one pin. It happens something when you plug in the IC into the IC sockets.

Do not connect the psu directly to the console. Do everything with the psu turned off. Don't touch any part inside of the psu. Plug off the power before working.

Good luck!

(I can try to tell you how to measure the transistors with the diode function of a cheap multimeter... but thats not easy if you never did it before... and you need to remove the transistors anyway.. so changing the transistors is as much as fast probably)

Frank.

Have you tried http://forum.analogconsole.com ?

Third from top is dedicated to D&R consoles.

Jim

Think it has been on the forum before and if I recall it right is had to do with a blown IC.
Maybe you could contact Hans Rosen, a member here, he had this problems and solved them.

Willem.

Thanks so much every one for replying.

I've been swamped at the studio and haven't had a chance to look at everything.

I will hopefully have time on the weekend to have a go at fixing it. I think i will replace all the IC's and go from there...

Cheers

Chris

O.K so i solved the power supply!

It's running fine but know i burnt out R305 on the Master module. So there is something wrong with the master module. I blows even if i only have the single PCB that the power connects to (not the whole desk/master module. So the problem lies there.

What should i be testing and looking for?

Thanks so much for your help!!!!

Best thing to do is to remove all IC's from the sockets, replace the resistor, who works as a fuse, and putting the IC's back in again
one by one.
You can visually inspect the IC's with a magnifying glass to see if there are cracks in them.
Eventually you will find the faulty IC because that resistor starts smoking again.
Know this is time consuming but I do not know how to do it another way.

I do have a master section for spare, but not with the balanced outputs.

Best regards,

Willem.

Good work! What was wrong with the psu? Transistor 3 (2n3055) ?

R305 seems to be the resistor for the Solo LED.
Its connected to the negative 17V psu rail and limits the current for the solo led.
Check the Solo LED in the mastersection. Its possible that the legs of the LED are connected to each other?
Plug in one input channel and put some audio signals with a DI-BOX into the mic preamp or so and see what works and what not. If there is an audio signal at the master LEDs, good. Check if the SOLO function is working or not.

Frank.

Yep it was th 2n3055!

I'll check the solo LED in the morning.

Thanks so much everyone for your help!

I've just started reading some Electronic books so hopefullly i can repay the favor some day  ;D

Hi Guys,
I got some problem with the D&R too. The Master left LED is doesn't work any more ! I need to change the IC 3 [VAA180]? or do you have any idea ?
PSU is showing  -17.75 / +17.50 ! is it ok or I need to do have -18/+18 !?
Thanks !
                             

I can help you: http://www.groupdiy.com/index.php?topic=44172.msg552339#msg552339.
Love D&R and I have already worked on D&R consoles

reanimatorstudio said:

I can help you: http://www.groupdiy.com/index.php?topic=44172.msg552339#msg552339.
Love D&R and I have already worked on D&R consoles

Click to expand...

Thanks reanimatorstudio ! Great !
cheers,