Testing a lm324

datafry

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What's the best way to test a lm324 op-amp? I have some sound issues and I think it may be the op amp. But I'd like to test it some how before I pull the boards and do a solder job.

Cheers
Kevin
 
What's the best way to test a lm324 op-amp? I have some sound issues and I think it may be the op amp. But I'd like to test it some how before I pull the boards and do a solder job.

What I've done is inject a signal into the input of the op-amp and then see if you get a tone out, well listen for the tone anyways.. Of course this does't take into account a bad audio amp or speaker, but I'd assume those had been tested first ;)

- James
 
What I've done is inject a signal into the input of the op-amp and then see if you get a tone out, well listen for the tone anyways.. Of course this does't take into account a bad audio amp or speaker, but I'd assume those had been tested first ;)

- James


Yep yep, it's really easy... MUCH easier if you have a signal generator or can whip one together real quick...


Out1 --+---+-- Out4
Neg1 --+...+-- Neg4
Pos1 --+...+-- Pos4
Vcc+ --+...+-- Gnd-
Pos2 --+...+-- Pos3
Neg2 --+...+-- Neg3
Out2 --+---+-- Out3


Listen on the outs, put the signals in on the in... probably best to put whatever game your try'ng into test mode so you don't have any other audio on the lines... Send the signal in, and listen to how it comes out. The crap signal generator I have has outputs directly from the generator for you to hook up to a speaker or an earbud, makes it easier to compare the sound, but odds are you won't need anything like that... most of the time, it'll either work, or not work. If it's dirty, you should be able to tell right away.

I just had to do this this afternoon on my TMNT boards... both amps were decent, one was a little iffy, but not enough to cause my lost sounds. I'll replace them anyways, but it's nice to know they weren't causing the issues.

Best of luck.
 
I just play some sounds from the game and use an oscilloscope to follow the signals.
 
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