My friends ADA8000 burned up an op amp on channels 5 and 6 only.

[AUDIO FREQ]

I checked all the other channels, and it seems like only 5 and 6 are very weak in signal. I switched out the op amp for another 5532 and it seems to still be very weak signal.

Why would it only burn up one op amp? Strange.

Anywho, I installed heat sinks and thermal pads on the three 7805s at the corner of the board. So I hope it keeps his ADA8000 alive still.

 

[Khron]

Input? Output?

 

[pucho812]

Are the caps ok? Visual inspection is not enough, test them out

 

[AUDIO FREQ]

Input? Output?

Hey Khron, this was the dual channel input op amp. The output is a quad channel.

Im gonna tear it down and take a closer look.

 

[JohnRoberts]

Look for a possible solder bridge short circuit loading down the op amp output. In that case the op amp might run unusually hot.

JR

 

[AUDIO FREQ]

Look for a possible solder bridge short circuit loading down the op amp output. In that case the op amp might run unusually hot.

JR

Roger, gonna put it under the magnifying glass to see. Im blind when it comes to smd parts.

 

[chilidawg]

I checked all the other channels, and it seems like only 5 and 6 are very weak in signal. I switched out the op amp for another 5532 and it seems to still be very weak signal.

Why would it only burn up one op amp? Strange.

Anywho, I installed heat sinks and thermal pads on the three 7805s at the corner of the board. So I hope it keeps his ADA8000 alive still.

Because channel 2 to 8 are basically just an exact copy of channel 1, you should measure every resistors and capacitors on channel 1 (in circuit), then compare their values with those on channel 5 and 6. Replace that is measured not the same.

 

[cyrano]

You seem to have a newer version. Are the two boards still interconnected with one flatcable per channel?

Then it's easy to test if the fault is on the preamp board or not by just changing cables.

One of my last repairs was my ADA8000 that had a weak channel 7. I couldn't find anything on the preamp board. IIRC it was something on the ADDA board.