7i76e defect (poti on TB4)

Hi,

I got my 7i76e 3 weeks ago.
First dry runs with inputs and outputs together with linuxcnc were successful. Until now
Yesterday I tried to play with TB4 potentiometer, but without success.

I connected a 9V Battery (9.2V) between Pin 1 and 3. And I always measure 4.55 V between Pin 1 and 2.
Regardless of the status of hm2_7i76e.0.7i76.0.0.spinena and hm2_7i76e.0.7i76.0.0.spinout.
Even when 7i76e is powered off, I measure 4.55 between Pin 1 and 2.

Am I'm doing something wrong?
Or does that indicate a defective 7i76e?

Thanks in advance.

If you get more than 100 mv or so on TB4 pin 2 relative to pin1
when not enabled its likely that the output buffer Op Amp is damaged

Hi tommylight,
+9.2V connected to pin 3
- connected to pin 1
4.55V (always) between pins 1 and 2

Hi PCW,
how do you know all the things about Mesa cards?
Do you own schematics of this cards?

Anyway, thanks for your answers.
Then I guess I'll have to exchange the card.

---
I contacted eusurplus.com today, where I bought the 7i76e card 3 weeks ago.
They told me, first to contact Mesa (This email address is being protected from spambots. You need JavaScript enabled to view it.) with full description of the issue.
Let's see what happens next ....

Just in case you haven't put 2 and 2 together, the This email address is being protected from spambots. You need JavaScript enabled to view it. you were told to contact is the same PCW that replied to this thread a couple of messages up.

Now it works! I cannot believe that!

I wanted to make card ready for shipment and I removed 1st time *all* plugs (green and orange, also the ones I had never used before) from card, in order to better remove wires.
Give it a last try, was my thought.
I plugged only the connector with the battery into TB4 without powering the card itself.
Now I measured 5.9mV between pins 1 and 2.
Exactly as Peter said it should be.

Could the other plugs have had something to do with the issue?
At least I didn't see anything strange thing.
I removed and plugged TB4 several times. But not the other plugs.

I'll send separate email to This email address is being protected from spambots. You need JavaScript enabled to view it. about this.

Hi Todd,

meanwhile I put 2+2 together
I already noticed the similarity when I was told to contact This email address is being protected from spambots. You need JavaScript enabled to view it..
This explains Peter's outstanding knowledge about Mesa cards.