Reads 1.0 at 200M range for both A and B with black probe on mounting hole

 

Without removing anymore resistors, do the same measurement on all the remaining SMD 1000 resistors for all 10 opamp circuits.

Please set the ohmmeter to 20K Ohms range.

 

At 20K range, every SMD 1000 in the op amp area read 1 (20 measurements).

 

Ok. We're not beaten yet.

We have to do the same test with the +5V supply rail.
We need to find where is the +5V supply rail that connects to VA on pin-9.





Look visually to see if there is an obvious track between pin-9 and the capacitor.
Check with the ohmmeter for zero ohms between pin-9 and the capacitor.

 

Pin 9 goes to the through hole right above it.

the capacitor has zero ohms to pin 6 on logic

 

Ok, if both pin-4 and pin-9 are connected via the holes above them, use one of the holes as your next check point.

Connect the RED lead to the hole.
Connect the BLACK lead to the 20 resistors as before and check the resistance in the 20K-ohm range.

 

Attached this to show the tracks

 

I connected the red probe to pin 9 then 20 resistor measurements at 20K all read 1.0.

i did the same for pin 4, same reading; 1.0

 

Ok. Thanks. We'll take a break and continue another time.

In the meantime, consider having to remove the CS5368 IC.
Also you will need to get some solder wick and a flux dispensing pen.

 

I connected the red probe to pin 9 then 20 resistor measurements at 20K all read 1.0.

i did the same for pin 4, same reading; 1.0

Was the reading 1.0 or 1?
They mean two different things.

 

Both are in house. Should I have it removed before we resume?

 

Was the reading 1.0 or 1?
They mean two different things.

the reading at 20K was 1 not 1.0

 

All the tests we did today did not reveal any problem.
Your original observation was that one CS5368 was getting hotter than the other. This could be significant.

We cannot proceed until the -12V supply rail is fixed.
Removing the suspect CS5368 will allow us to continue trouble shooting the -12V supply rail. Once that is resolved we should install a new CS5368.

 

Thank you for the wrap up!
I’ll have it removed before we connect again.

 

Thank you for the wrap up!
I’ll have it removed before we connect again.

If you care to proceed, remove the CS5368.
Install the 10R0 resistors (while replacing the bad one).
Apply power and measure the voltages at each end of the resistor with respect to ground.
We are looking for +12V and -12V.

 

With the CS5368 removed and if the voltage readings are indeed +12 and -12V, does this mean the CS5368 is the bogie?

 

I hold my verdict for later.
There are two voltage regulators on that board that need to be checked.

 

Ok, I think I fried the Audio IO.
As seen in the photo, I removed the IC, cleaned the legs really well to avoid shorts there, and reinstalled the resistors after checking their resistance.

the burn happened in the opamp areas, I switched off very quickly to avoid damage to the mother board.

at this point, I’m inclined to purchasing the Audio IO board and see what happens.
any thoughts from your end?

I appreciate the help all along. I knew before this happened that this may happen, and my plan b was to buy the board.

 

I cannot see the burnt areas. Can you point that out for me?

 

As soon as I poswered it I saw traces of smoke in a few spots. I shut it off.
I thought maybe it was the flux but then this area made a fire red mini spot and that's when I decided to not try it again.