AOUT NG Troubleshooting

MIDIbox SEQ
1

Hey guys,

I am looking for some help. I have a MBSeq4 with an AOUT NG connected with the line driver/receiver. 6 of the channels are working perfectly, but I have two issues:

When I test the calibration for each channel with the output set at 8V, I get a constant 11V at output 5, and 0V at output 7. 

I have checked continuity between the outputs and the opamp, along with verified the resistance. I have also verified continuity between the opamp and the DAC.

When I measure the voltages on the DAC pins for a working channel, I get 3V. When I check output 5, it has 4v, and output 7 has 0V.

Do you guys think I fried these two pins on the DAC?

2

 

Hey

1 hour ago, goyousalukis said:

Do you guys think I fried these two pins on the DAC?

To me it look like…

There is not that many part at AOUT_NG… the weakest being the DAC

Just double check your measure at TLV5630 output with the TL074s removed

Best

Zam

 

 

3

I agree with Zam: probably those DAC channels are dead (but do check directly at the pins). The TLV chip is quite sensitive to heat.

4

Thanks guys - I havent had a chance to pull the OpAmp and recheck the voltages yet. I’ll probably just settle for 6 CV outs.