Behringer DDX3216 - Trying to repair, please help!

[EEngo]

Here some examples of the interface communication. Response from an ADT16-Card:



Command to ADT16 to change output bus: (1-8, 9-16 or MIX-Bus, this is done for both module addresses (0xCE or 0xCF):

[paulflan79]

unfortunately I'm not that experienced with the arduino programming language so will have to learn, good job i'm in no hurry as i see frustration ahead, i got a raspberry pi about the same time and it just seamed easier for me to get on with and experiment but then i've played with computer's for the last 15+ year's with Linux etc, why couldn't behringer of just used a basic boot loader and linux kernel

seem's i'm going to be digging it back out and giving it a go with a new purpose,

the expansion slot's have 50 pin connector's on looking at the service manual i have, however it dose appear incomplete unfortunately,

Pin 1 Gnd
Pin's 2 to 31 are all the different I2s data busses for I2SIN 1-16 and I2SOUT 1-14 respectively
Pin 32 LRCLK_IO (can this be hard wired straight to the same pin's on the ANAIN & ANAOUT boards with no other logic with it being a high frequency clock ?)
Pin's 33,35,27,39,41,44 are all ground's
Pin 34 BCLK_IO (can this be hard wired straight to the same pin's on the ANAIN & ANAOUT boards with no other logic with it being a high frequency clock ?)
Pin 36 M256_IO (I2s Master clock? as all DAC's are wired to slave mode) (can this be hard wired straight to the same pin's on the ANAIN & ANAOUT boards with no other logic with it being a high frequency clock ?)
Pin 38 SYNC_EX* *=A FOR SLOT 1 & *=B FOR SLOT 2 (what is this and will i need to use it please, is it if you want to use an external clock source or something ?)
Pin 40 TX
Pin 42 RX (i take it this is the transmit and receive data buses that is used for communication and what i need to hack in order to spoof the mixer into thinking there's an expansion card fitted and to activate the relevant I2s busses)
Pin's 43 to 50 are providing power

and the ANAIN board has a 26 pin connector, (16 channel input board with ADC's etc)

Pin's 1,3,5,7,9,11,13,15,17,19,21 all tied to ground
Pin 2 LRCLK_IO (again can all the I2s clocked be hard wired straight to the same pin's on the expansion slot board with no other logic with it being a high frequency clock ?)
Pin 4 BCLK_IO """" """"" """"" """"
Pin 6 M256_IO """" """"" """"" """""
Pin 8 I2SIN1 (Ch's 1&2 - i think this is correct anyway ?)
Pin 10 I2SIN2 (Ch's 3&4)
Pin 12 I2SIN3 (Ch's 5&6)
Pin 14 I2SIN4 (Ch's 7&8)
Pin 16 I2SIN5 (Ch's 9&10)
Pin 18 I2SIN6 (Ch's 11&12)
Pin 20 I2SIN7 (Ch's 13&14)
Pin 22 I2SIN8 (Ch's 15&16)
Pin 23 RESETAD (this isnt used on the expansion card connection but may be of use ?)
Pin 24 ANON18 (any ideas what that is ? enable Ch's 1-8 ?)
Pin 25 ANON916 (again any ideas ? enable Ch's 9-16?)
Pin 26 SPDIFO (take it that's for spdif on the rear using the little interconnect to the ANAOUT board)

and finally the ANAOUT (analog output board with DAC's etc)

Pin's 1,3,5,7,9,26 are all tied to ground
Pin 2 WC_IN (word clock input however wont be using this)
Pin 4 WC_OUT (word clock output however wont be using this)
Pin 6 LRCLK_IO
Pin 8 BCLK_IO
Pin 10 M256_IO
Pin 11 I2SOUT13
Pin 12 I2SOUT1 (AUX 1&2)
Pin 13 I2SOUT14
Pin 14 I2SOUT2 (AUX 3&4)
Pin 15 I2SOUT15
Pin 16 I2SOUT3 (MAIN STEREO OUTPUT)
Pin 17 I2SOUT16
Pin 18 I2SOUT4 (MONITOR OUT)
Pin 19 RESETAD (appear's to be a mute pin ?)
Pin 20 SPD0
Pin 21 SPDI
Pin 22 SPCLK
Pin 23 SPCS
Pin 24 SPLTCH
Pin 25 SPDIFI

i'm missing part's of this board in the service manual i've downloaded so i'm unable to check what it is exactly pin's 20,21,23,24,25 are actually doing so apart from the I2s pin's im unsure of the rest and im only actually interested in using the DAC's to give extra analog output's, i'm thinking Pin's 20,21,22,23,24,25 are related to the SPDIFF in/out that i'm not to bothered about if it's going to be a pain to get them working
and wonder what the other I2s busses are for ? could try it with the raspberry pi in needed,

I've already got a single Adat card fitted in one of the slot's i use with a computer sound card however only really use 8 channel's of it for recording and hoping at the end of all this to have 32 analog input's and possibly an extra 8 analog output's and be able to assign them all as and when required,

and thank you, your help is very much appreciated as this is a steep learning curve for me
However i did get both mixers cheap enough to make it worth me having a go

[EEngo]

I recommend looking for the complete schematics. Because there were no programmable parts used in the ADC or DAC section, in addition to the part datasheets you can find out which signals to use very easily.
Do you have an oscilloscope? With these (moderate) high-speed signals it may be important to check signal integrety when using long cables between the units.

good luck!

PS: I still have a CPU left, if you want to replace the fried one , otherwise, I would be interested in the damaged CPU card or other parts of the non-working DDX. Maybe I could send you an "expansion card simulator" on arduino basis, If you don't want to dig into arduino programming. If of interest, send me a PM.

[paulflan79]

Well to be honest i don't fancy my chances on replacing the CPU due to the fine pitch and chances of unforeseen bridging of pin's and destroying yet another CPU so the board's kind of useless to me, so PM me if ya interested

and yes i was aware that there was no programmable part's on the ADC & DAC boards that started me thinking would this modification work and started looking into it however ran into the issue you have investigated,

The other pin's on ANAOUT Pin's 20,21,22,23,24,25 do appear to be for the SPDIF I/O so not of interest to me really

I only have an old analog 15Mhz scope as i normally just stick with analog audio unless it's well documented however i love learn

im only looking at extending the digital link by maybe 30-50cm to connect the extra 16 channel input board and building my own case where they are facing you right above the existing inputs directly above the expansion slot, would that still cause issues with timing on the clock/data lines ?

any ideas on getting something that would fit the 50pin expansion socket so i wouldn't have to take my working mixer apart and modify it or is it proprietary ?

[EEngo]

unfortunately, I haven't found the connector yet

It would be very interesting when you tell us your experiences with your expansion

[EEngo]

@paulflan79: Unfortunately, I cannot send you a pm
I could send you an arduino board with the software programmed into already.

[paulflan79]

I don't know why you couldn't send me a PM ?


To be honest i don't know how i feel about taking a perfectly working mixer apart that i actually use to experiment with, hence me asking was the connector proprietary and it appear's to be fine pitch

however if i did decide to do this modification i could always prepare the back plane from the mixer i'm salvaging for part's removing one of it's proprietary slot's and possibly use a short length of ribbon cable and just open the working mixer just to exchange that single board at the rear,

Thank you however i can buy arduino board's really cheap locally and it's just the IDE coding environment and use of what if any libraries etc that quickly looses me/my interest upto yet

would the arduino be connecting to Pin's 40 (TX) & 42 (RX) and ground on the 50 pin connector for communication with the microprocessor of the DDX 3216 as the rest of the pin's are power, ground and I2S clock and serial data I/O lines ?

only i am stepping out of my comfort zone and don't want to risk braking my working DDX3216 on a chance this may work without proof of concept, help and guidance

and it's then a question of how to integrate a DIY 16in 8out and a Behringer ADT1616 ADAT Option Card ? would the DDX3216 firmware cope with that providing the routing options in the menu system to choose between the 48 inputs and 32 output's cos are each I2S I/O signal on it's own buss directly to the DSP and then dealt with ?

thinking about it, it would probably cope as you can fit 2 ADT1616 card's however the expansion slots each have 16 I/O channel's each and not 16 in and only 8 output's like im wanting to use ?


Is there anyone else interested in this project ?

this would open this cheap second hand digital mixer up for some killer DIY mod's providing analog I/O of your choice, pick your preamp design and ADC's
as you could then build your own preamps and choose the ADC of your liking or look into salvaging them specially as prices continue to drop or even free for obsolete, outdated or spares & repairs for interfaces with proper nice sounding front end pre-amp's and ADC's to be salvaged if there internal circuit board's are made in a modular fashion with service manual's available

[g1]

I don't know why you couldn't send me a PM ?

He can now. For new members the PM function doesn't work for awhile. Yours is now working.

[paulflan79]

thank you for clearing that up, very much appreciated

[Phoebus1966]

I replaced the CPU chip. There was/is? a an ebay store which sells exactly the chip type needed (ELAN SC300-SC). I used a hot air station to remove and a conventional soldering iron and a microscope to solder the new one. There are several videos on youtube which describe soldering such devices.

I have still one new chip left, if you want to try it

Just a thought as I read through the thread here. Do you believe a faulty ADT1616 expansion card might have been at the source of a CPU dying?

I find the fact a VLSI just dying out of the blue odd but my commercial/industrial experience is also neglible.

If Behringer designs with insufficient design consideration causing levels frequently going beyond max ratings then the ADT1616 I bought seperately online may be the culprit. I see many signals from and to the CPU going about unbuffered.

[paulflan79]

I personally don't think an ADT1616 or any other expansion card could kill the CPU as looking at the 50pin connector pin out most of them are relating to the digital audio I2S busses leading to the DSP board and power and there's only a TX/RX on pin's 40 & 42 going to the CPU,
I'd say it's more likely a power supply issue maybe due to the increased demand's on it after fitting the card,
is it turning on at all or even attempting to start up ?
if it's getting as far as displaying the DDX3216 on the screen and freezing try replacing the watch crystal on the CPU board
as stated me and EEngo unfortunately plugged in the wrong power connector into the CPU board when putting it back together and turning it on

[EEngo]

yes, I think you are correct.
the most probable (and definite!) cause for a dead CPU is using the wrong power cable. I don't think there is a second way to fry a CPU in general use. As the CPU is not consuming a lot of power in normal operation, a heat-related failure is also very unlikely.

The main problems of the DDX are still heat in the power supply (therefore failing caps, regulators and diodes in the power supply), failing caps in general (especially on the LCD board) and a swapped power connector on the CPU card after cap exchange

I have checked with a thermal camera, but there are no heat issues with CPU or DSPs. Apart from the power supply the ADCs are running hot, too, but I have never seen a failed ADC so far.

[Phoebus1966]

yes, I think you are correct.
the most probable (and definite!) cause for a dead CPU is using the wrong power cable. I don't think there is a second way to fry a CPU in general use. As the CPU is not consuming a lot of power in normal operation, a heat-related failure is also very unlikely.

The main problems of the DDX are still heat in the power supply (therefore failing caps, regulators and diodes in the power supply), failing caps in general (especially on the LCD board) and a swapped power connector on the CPU card after cap exchange

I have checked with a thermal camera, but there are no heat issues with CPU or DSPs. Apart from the power supply the ADCs are running hot, too, but I have never seen a failed ADC so far.

Then mine is the exception to the wrong power cable. The CPU just went dead out of the blue during a mixing session and others have had the same happening to them. Sudden death of CPU with X-mass tree lights as result. Mines also had the LCD going blank but rolling like with a bad horisontal synced crt screen. That was say 20 minutes after the unit had a used ADT1616 plugged into it and working fully! Mind you, no power cable switching or whatever involved here. When I was about to litepipe it with a Yamaha AW4416 I suddenly saw with the white of my eyes something odd happened to the DDX. And that was it.

[paulflan79]

[QUOTE=I'd say it's more likely a power supply issue maybe due to the increased demand's on it after fitting the card[/QUOTE]

i personally would say it's probably due to the increased demands on the ageing power supply after fitting the extra card's that was probably already on it's way out, as EEngo stated, the built up heat cannot escape from the power supply enclosure and cooks the capacitor's dry, the smoothing cap's are common resulting in increased ESR and thermal runaway as thay basically become more like a resistor in circuit made worse by increased load creating unstable/noise on the DC output that would be sending the CPU unstable mainly i'd check the 3.3vdc and the 5vdv as i'm shore they also power the expansion slot's to see if there in spec and if there's any ripple/noise/AC or increased voltage or spikes on the power supply that could be responsible,

as i asked before, "is it getting as far as displaying the DDX3216 on the screen and freezing ?" or is the unit just totally dead ? lighting up like a Xmas tree with a black screen ?

what makes you think the CPU is dead ?

[Phoebus1966]

i personally would say it's probably due to the increased demands on the ageing power supply after fitting the extra card's that was probably already on it's way out, as EEngo stated, the built up heat cannot escape from the power supply enclosure and cooks the capacitor's dry, the smoothing cap's are common resulting in increased ESR and thermal runaway as thay basically become more like a resistor in circuit made worse by increased load creating unstable/noise on the DC output that would be sending the CPU unstable mainly i'd check the 3.3vdc and the 5vdv as i'm shore they also power the expansion slot's to see if there in spec and if there's any ripple/noise/AC or increased voltage or spikes on the power supply that could be responsible,

as i asked before, "is it getting as far as displaying the DDX3216 on the screen and freezing ?" or is the unit just totally dead ? lighting up like a Xmas tree with a black screen ?

what makes you think the CPU is dead ?

DC voltages on its pins and memory chips. Not a black screen. Fixed but random horizontal lines. And sometimes (seldom) when switching off and on again you'd get a rolling blank screen as like with crt screens with bad H-sync. Then the CPU has no dc on its pins and memory pins. This indicates something is running but never I get the DDX boot screen. Oh, and that is with the CPU board neatly separated powered by a stable power supply. The CPU board is actually a classic PC board working on the classic voltages it gets from a spare PSU I have: +/- 12v, +5 v, +3v3.