How do we check IC on the PCB working or not?

[aarvy]

Hello,

How can I check that some ICs on PCB works properly or not? Can I turn off the power supply and then by giving necessary inputs and checking outputs? My PCB contains ARM Processor and few Op-amp ICs. I need to check Op-amp IC. I do not have any other testing equipments. 

[David_AVD]

Wave a dead fish over it?   

I think you'll need to supply more details to get a sensible answer.   

[Skimask]

Wave a dead fish over it?   

oooo.....  I like that.  Going to try that next time I've got a problem.
 
Now...where to find dead fish....

[aarvy]

Well, PCB has few ICs ( Op-amps, Driver, Voltage regulators etc). Now I want to check the IC is in working condition or not.
Problem: IC is already connected to other ICs on the board. If I will give some INPUT to IC and then check OUTPUT of the IC, can I check this way? ( What if current would flow from this IC to the other part of the PCB ?!  )

[tautech]

You could try the "razor blade" technique on individual IC's.
Slice signal path tracks (in & out), provide test signal and measure output.
Solder over slice when the problem is fixed.

[Dago]

Usually something like this is taken in to account when designing the prototype. Putting resistors/jumpers on lines so you can desolder them and feed a different signal. Also putting in a ton of test pads never hurts.

[rob77]

Wave a dead fish over it?   

oooo.....  I like that.  Going to try that next time I've got a problem.
 
Now...where to find dead fish....

i think the best source for extremely dead fish is this  (extremely dead - judged by the smell (stench?) )
http://en.wikipedia.org/wiki/Surstr%C3%B6mming

but to the OP's question - just measure the in/out voltages of the opamps in-circuit  and compare the readings to the expected values.

[owiecc]

Can I turn off the power supply and then by giving necessary inputs and checking outputs? My PCB contains ARM Processor and few Op-amp ICs. I need to check Op-amp IC. I do not have any other testing equipments.

Turning the power on helps with debugging. Checking an opamp is quite straight forward. Check if correct voltage is present on power pins. Locate the inputs and check if the voltage difference is zero with a multimeter. Check also is input voltages are within the acceptable range.

[Bassman59]

Hello,

How can I check that some ICs on PCB works properly or not? Can I turn off the power supply and then by giving necessary inputs and checking outputs? My PCB contains ARM Processor and few Op-amp ICs. I need to check Op-amp IC. I do not have any other testing equipments.

Well, if you want to test an op-amp, the usual thing to do is to give it an input signal and look at both the input and the output on an oscilloscope.

[jamesglanville]

Can you not just write some test code to run on the ARM? It should be quite possible to get the ARM to send a range of signals to the opamps and then probe the outputs with an oscilloscope.

[David_AVD]

The OP is possibly another "post and run" guy.  No easy instant result and they haven't been back since the day of posting.  Seems to be a few of those lately.

[Bassman59]

The OP is possibly another "post and run" guy.  No easy instant result and they haven't been back since the day of posting.

He got an answer he didn't like. He did say, "I do not have any other testing equipments," and of course every reasonable response said, "Look at it with your oscilloscope."

[Skimask]

The OP is possibly another "post and run" guy.  No easy instant result and they haven't been back since the day of posting.  Seems to be a few of those lately.

"a few" is the understatement of the year!

[Smokey]

This is assuming NO other equipment....

Test #1)  Visually inspect.  Does it have a big hole burned in the top of the package?
Test #2)  Touch test.  Power up the board and tough the part with your finger.  Did it burn the hell out of you?

Passing these tests doesn't guarantee a functional part... But failing them is probably a bad sign