What are the odds? CMOS question...

[gutsofgold]

I recently was fixing an old "amp" circuit for somebody and traced it down to the 4069 inverter. It was a regular 16 pin P-DIP (?) version and I got it out just fine with a solder sucker. I put a Fairchild one back in, "UBE" unbuffered version, however I wasn't even thinking and didn't use a socket. I just soldered it right back in because the original one wasn't in a socket. Now I tested the amp and it worked perfectly fine...the problem was fixed and I gave it back to the owner. He called me a few minutes a go and said that nothing happened and it was completely ceasing to function again.

What are the odds that the CMOS chip worked for a few minutes and then "killed" itself? Can a CMOS chip like this be soldered to directly without problems or are the odds of it surviving the soldering very slim?

[bioroids]

I've soldered many CD4069 and they have all survived!
Maybe the thing that caused the original IC to blow is still acting and blowing CMOS chips?

Regards

Miguel

[snap]

Nationals 4069 are 14 pin
http://pdf1.alldatasheet.co.kr/datasheet-pdf/view/80428/NSC/CD4069.html   

[earthtonesaudio]

Maybe the thing that caused the original IC to blow is still acting and blowing CMOS chips?

+1.  Wise words...

[Paul Perry (Frostwave)]

Check the voltage going to the power pin on the chip.
Some circuits run them pretty close to the absolute maximum, and the maximum supply voltage can differ between manufacturers, I believe.

[grapefruit]

Some circuits run them pretty close to the absolute maximum, and the maximum supply voltage can differ between manufacturers, I believe.

Yes, I've come across this before with CMOS IC's. Usually it's not an issue because the supply voltage is low enough so that all brands will work ok, but at least one unit I've repaired had the operating voltage above the maximum of all but one manufacturers ratings.

Stew.