please tell me. What would be a good test circuit to see if the LT1012 is broken?
Moving to the op-amp forum.
If you want to verify basic operation, the simplest test would be to simply wire the LT1012 as a follower, with the non-inverting input tied to a 10k-10k resistor divider between the supply rails. Then power the device from a 9V battery (or benchtop power supply), verify that the output is at approximately 1/2 of the supply voltage.
This does not verify any of the actual analog specifications - the LT1012 is an extremely precise device, and each parameter (offset, bias current, noise, etc.) requires special test circuitry.
I think the device can only be damaged, if the limits given in the absolute maximum ratings has been exceeded. In such a case you can’t be sure if the device works as specified even if you try to test all of the features (which is practically impossible, anyway). A partial damage can be undetectable but can develop problems later, can make the device more sensitive. Therefore I think you should not try to test if it is damaged. Instead, if the absolute maximum ratings are violated, the device should not be used any more even if it seems to work properly. There is a good article about the subject in the rarely asked section (What’s the big deal about ABSOLUTE MAXIMUM RATINGS?).
Thanks ZoltanDTI, yours is the correct level of scrutiny. AD5686 take note - if you are trying to detect damage, or if there is any question that the parts are not genuine, then you are better off not to use them.
Note that the ONLY way to get a genuine, undamaged part is to purchase new through an authorized distributer. Even originally genuine parts that appear to be new, in a rail, but come through an unauthorized channel such as a broker or random vendor, are considered counterfeit. It is possible that parts were removed from the package, damaged, then returned to the package. It is also possible that some other op-amp was relabeled as an LT1012, and counterfeiters are quite sneaky.