Behringer DX3216 help needed

[3rddawn]

Just bought this secondhand, was assured that "it has only crashed once, a long time ago".

Left it on for a couple of hours to test that it was going to be ok to use live, it froze. When I turned it off and on again it was the same.
I left it off for a couple of hours, turned it on again and it was fine, fully functional.

Left it on for a few hours again, had frozen again. This time, no amount of waiting makes a difference.
On switch on, I get alternate lights on all the sections, LCD can be black, stripey or clear (different when switched off and then on again, at random).



I've taken out the power supply and tested all the voltages at each of the pins with a voltmeter, they all seem ok.

Close inspection shows that the PSU looks ok - there's only one suspicious looking capacitor (slightly domed on top, little mark in the middle - see photograph).



Any ideas what to try next?

Thanks
3rddawn

[Jazz P Bass]

That capacitor does look a little bit "domed".
Can you push down on it? (the cap)
If it moves back down, then that is possibly a bad cap. (hydrogen gas venting)
Not having the power supply schematic, I do not know the function of that particular cap.
Did you try testing the power rails with the unit hooked up?
If not, that is a good place to start.

[Steve Conner]

This is a DDX3216, right? Not a DX3216.

We had a big repair thread on these things a while back. There are several known faults. Use the search function to look for DDX3216.

[3rddawn]

Steve: Sorry that was my typo - it is DDX3216. I've read and reread all the threads before posting above. They don't seem to relate to my problem.

Jazz: Having found all the power rails seemed in order with no load, having hooked the PSU back up and tested it again, now I'm showing no lights or display or anything. The 8, 17, 48V all seem ok, but the 5V pretty consistently show 72mV across the connectors and the 3.3V ones are showing nothing.

I can do soldering etc, but just don't know enough about electronic circuits to know what to change.

The schematics of the PSU are available on the repair thread Steve mentioned. I'd repost but I've tried 4 times and my PC (in 2 different browsers) has decided to crash every time ... sorry!

Thanks for any help anyone can give.

Cheers
Lawrence

[diydidi]

Lawrence,
Almost certainly that capacitor!!!

[Steve Conner]

I agree, the capacitor looks like a sick puppy! I just saw it now, wasn't able to load the pictures before (my own fault, not the forum)

You might as well replace all of the big electrolytics.

[jrfrond]

That's a bad cap, and for the record, you should just recap the entire supply, using good caps e.g. Panasonic or Nichicon in 105°C temperature rating. You will need to physically measure the existing caps and compare them to the catalog measurements because they are a somewhat tight fit.

[paulos3030]

hi! i just signed in!
I have the same problem with my behringer ddx3216. error +1 8!
It started with my display going dark (slowly over time) until it was to hard to read. All the rest working just fine!!
i took some mesurements of the voltages and most of them were higher than they should be!
so i did a recup most of the psu (not all of them) and i reconnected everything back!
at bootup ,most of the led light up and i got error +1.8 ! i tried factory reset but it didn't work!
Can anybody please give me a hand with this?

[3rddawn]

I ended up sending it to Electronic Music Services in Southend on Sea, who sorted it out. Many caps needed replacing, they overhauled the PSU and sorted some other problems which had also appeared with some of the other boards. They were excellent, I'd highly recommend them if you're in the UK.
Lawrence

[JD13208]

Hi I am new here and have got this DDX3216 from a friend who said it was working perfectly and had shipped it to me.
When I unpacked and powered it up, everything came on except the LCD which only lights up abt half and is completly black.
Have been trying to fix the issue but I am not very experienced with LCD's
Is it a fault of the LCD or any other IC, PSU related issue?

Any help would be highly appreciated.

Thanks

[Jazz P Bass]

What on the LCD is 'lit up half way'?
Are all of the characters showing, top & bottom of screen?
Or is the backlight lit poorly?

[JD13208]

What on the LCD is 'lit up half way'?
Are all of the characters showing, top & bottom of screen?
Or is the backlight lit poorly?

Hi,

No there are no characters or graphics displayed just a black patch abt half way of the lcd.
Tried playing around with the connector and only get the LCD to partly go black.

Thanks

[Jazz P Bass]

Well, either the character generator IC (part of the lcd) is bad or someone took the LCD apart & did not assemble it correctly.
It can be real tricky reassembling an LCD.
The two silicone conductive strips have to be very clean.
And the tension of the frame has to be consistent all the way across.

[JD13208]

Well, either the character generator IC (part of the lcd) is bad or someone took the LCD apart & did not assemble it correctly.
It can be real tricky reassembling an LCD.
The two silicone conductive strips have to be very clean.
And the tension of the frame has to be consistent all the way across.

Thanks Jazz,

Will try taking the LCD apart anc clean the silicon strips and give it a try.
or could i just replace the lcd?

Thanks

[JD13208]

A
Also noticed the IC T6A39 gets very hot cannot touch it could it be the problem?