What to check before blowing another Opamp

I have a Summit 200 EQ. One of the 990 style opamps shorted it's OUT to -V. I'm wondering if as a general rule I should check anything before just putting the new one in and hoping for the best?

I don't mean to ask for someone to hold my hand... I'm just wondering if these style opamps short the output like this for a reason?

check current draw...

JR

JohnRoberts said:

check current draw...

JR

Click to expand...

Well, thats my question I think... how do I measure current draw without inserting the new opamp?

jwhmca said:

JohnRoberts said:

check current draw...

JR

Click to expand...

Well, thats my question I think... how do I measure current draw without inserting the new opamp?

Click to expand...

you could wire up just an ne5534 using wire soldered to its pins, just to make sure it wasn't anything else that fried it. I'd rather blow 0.25 cents and some time then a 100$ opamp...

abechap024 said:

you could wire up just an ne5534 using wire soldered to its pins, just to make sure it wasn't anything else that fried it. I'd rather blow 0.25 cents and some time then a 100$ opamp...

Click to expand...

Seriously? You can sub a 5534?

The 5534 might not like the +/-24V DOA supply, so better supply it from the +/-15V servo-op rails and place a 22pF between 5534-pins5/8 for unity gain compensation.
No schematic here, but assuming the EQ200 output stage is the same/similar as the DCL200, check the OP297 servo as well. Maybe your SA990C are fine and only the servo is shot.

You can add resistors in series with +/- power supply pins, or even fuses if you can find them small enough to detect high current draw before smoke gets released..

A DOA that is not properly biased ip right for quiescent operating current can over heat and self destruct. Another potential self destruct mode might be oscillation.

I am not a big fan of DOA especially when off the shelf parts work so well, but opinions vary. 

JR