Semi-Dead Behringer ADA8000

torreznor · Jan 17, 2016

Hello everyone. My ADA8000 has died on me for the second time. Same problem as the first time, but first time it was in warranty period and it was repaired by Thomann. Now I have to do it myself and I don't have much of a clue.

It's a rev G model. I switched it on and the lights shined dimly, with half of the usual brightness. I thought it was just my impression but I tried to record throught it and it wasn't working. I tried to find some info in the internet and found this post.

I brought the device to an uncle of mine who is very technically skilled. We have opened the thing this afternoon and checked the voltages of the regulators. Every tension seems to be ok but one, the +5va, which measured at the phantom led indicators is reduced to 3,39v. We have followed the tracing and arrived to the T19 transistor in reverse of the main board, but we are not able to find such component in the schematics we own.

http://noiseshome.dmz.ro/files/2010/11/Behringer_ada8000_diagram_schematics.pdf

I posted this very question several months back here but got no answer.

http://groupdiy.com/index.php?topic=11319.msg748304#msg748304

Could anybody shed some light on the issue? Thanks in advance for your time!

Khron · Jan 17, 2016

Does the +5Va come directly from the power supply? Or is it the output of one of those regulators?

SkunkFunk · Jan 19, 2016

My unit, dont know revision number, died a few months ago. It was all about bad caps. I used my ESR meter and found that the closer the caps were to the power supply, the higher ESR. It was quite amazing that this was the case for all ~50-100 caps on the main board. And the bulk caps closest to the regulators were completely dried out. Changed all caps to Panasonic 105 degrees, fixed the problem.

Don't know if this is any help or not, but I suggest you check the caps, especially those that risk running hot in the PSU.

Khron · Jan 20, 2016

Well, they "gotta" cut corners SOMEwhere, to get to those prices... ;D

ln76d · Jan 20, 2016

R.I.P behri-behri...

Whoops · Feb 2, 2016

torreznor said:
Hello everyone. My ADA8000 has died on me for the second time. Same problem as the first time, but first time it was in warranty period and it was repaired by Thomann. Now I have to do it myself and I don't have much of a clue.

It's a rev G model. I switched it on and the lights shined dimly, with half of the usual brightness. I thought it was just my impression but I tried to record throught it and it wasn't working. I tried to find some info in the internet and found this post.

I brought the device to an uncle of mine who is very technically skilled. We have opened the thing this afternoon and checked the voltages of the regulators. Every tension seems to be ok but one, the +5va, which measured at the phantom led indicators is reduced to 3,39v. We have followed the tracing and arrived to the T19 transistor in reverse of the main board, but we are not able to find such component in the schematics we own.

http://noiseshome.dmz.ro/files/2010/11/Behringer_ada8000_diagram_schematics.pdf

I posted this very question several months back here but got no answer.

http://groupdiy.com/index.php?topic=11319.msg748304#msg748304

Could anybody shed some light on the issue? Thanks in advance for your time!

That schematic you showed it's a traced schematic of the Ad and DA converters only, it's not the schematic of the complete unit.
where in the circuit is located that T19? it's in the PSU section?
Can you read the reference on top with a magnifying glass?
that T19 transistor is probably the same as T20, can you read the reference on that one?

Do you have a Peak DC75 to test transistor or can borrow from someone? then you could desolder the transistor and tested it with the DC75