I've been working on a discrete op - amp for my project. It works fine when its on a breadboard, but when i solder it, it stops working. I've built the same thing three items now, and same thing happens. I know that the connections can't be wrong. Does this have to do with the extra capacitance that the breadboard has that the perf board doesn't? which is helping the op amp work better. I can't seem to figure out what the problem is. Any suggestion would be helpful.

 

Solder bridges on your board?

 

I know that the connections can't be wrong.

An extra set of eyeballs might see something you're missing. In my experience the thing you "know" is right is usually where the error is.

Anyway, how about a schematic and a photo?

 

Could be ESD, could be too much heat, could be bad solder joints or bad board design. Like wayneh said, post a schematic and clear photos of the board.

 

Could be ESD, could be too much heat, could be bad solder joints or bad board design. Like wayneh said, post a schematic and clear photos of the board.

...or it could be oscillating. We need a schematic, photos, and a description of what it is supposed to do...

 

My bet is on you overheating the ic when soldering. Assuming "doesent work" = dead

 

Does this have to do with the extra capacitance that the breadboard?

That was my first thought. Capacitance in the right place can stop it from oscillating. Capacitance in the wrong place can make it oscillate. Even some tiny little pfs of capacitance can make all the difference in certain critical positions.

Schematic and photo, please.

 

solder in a IC socket, then plug the IC in.

 

90% chance there's a mistake in your soldered version.

 

incorrect counting IC pin numbers.

Ramesh

 

its a 8pin DIP package? soldering each pin just once?
1) what type and wattage iron?
2) how long does it take for iron on pin to make the solder flow?
3) what type of board is it?

 

Start here!

An extra set of eyeballs might see something you're missing. In my experience the thing you "know" is right is usually where the error is.

Anyway, how about a schematic and a photo?

Ramesh

 

I was hoping the OP would come back on this one, I had the same problem and never did find a solution in spite of successfully making several of the same circuit some years before.