I have a project where i require to capture the difference between a functional L293D and malfunction L293D. For the malfunction, i take out the chip and zap it with 14vdc. Then after i capture the image, it shows that the chip that got zapped is colder than the others. is this a valid thing?
the malfunction chip is on the right side of the board
Interesting but not accurate. The part is rated at 36 volts. If you want a better answer post a schematic, not a frizzy drawing showing your circuit and explain the zap process. Also include all connections in your schematic. That is a nice picture of a circuit board but what is it?
Yeah, that's a rather strange expectation which requires a lot more explanation. 
My experience with blown driver chips is they get hot, not cold. May I haven't learned
how to damage them correctly ...
Hi
Or cold if they have split and let the smoke out, then its an optical observation that it is no more....But that can be fixed these days.
Tom... 
sorry, i dont have the schematic. i can only provide the infrared picture and the actual picture. i try to include more details:
i separate the chip from the board by pulling it out, the far left one. (the one that i circle)
then i zap every leg with 14vdc wet cell battery.
i put it back onto the slot and the board cannot run the motor anymore.
could it be that the circuit inside it blown and disconnect it self?
Sorry, i dont have the schematic. i can only provide the infrared picture and the actual picture. i try to include more details:
i separate the chip from the board by pulling it out, the far left one. (the one that i circle)
then i zap every leg with 14vdc wet cell battery.
i put it back onto the slot and the board cannot run the motor anymore.
could it be that the circuit inside it blown and disconnect it self?
Hi,
You need to look at how ICs are constructed.
They have fine gold wires and/or strips connecting the pins to the semiconductor substrate, you would have fused those most possibly, making then open circuit, so no current flow, no energy dissipated, when inserted back into circuit.
Tom...
i think it make sense as for the duration between i zap and i capture the images is 1 week apart
No, because it might run hotter, or the same temperature, by chance - the datasheet won't say anything about the behaviour of a damaged device, unsurprizingly 
There are various failure modes some might jam the device hard on, some hard off, others might happen to get stuck in an intermediate state, there's little to be gained worrying either way unless you are characterizing failure modes for reliability engineering I'd have thought.
How big is your budget, the semiconductor manufacturers spend a lot of money just to test and guarantee the final produce. What parameters do you want to check, how do you define a malfunctioning chip? What test fixtures do you have? Do you have environmental chambers to do both temperature and shock testing? What are your guard bands?
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