Bad CA3080?

[banjerpickin]

Hey guys - working on a dyna comp (ross version) and I'm getting no sound when engaged.  Went to test the volts on the pins, and 5, 6, and 8 are way off:

P1 - 0.06
P2 - 4.1
P3 - 4.1
P4 - 0.06
P5 - 0.06 (should be .65)
P6 - 6.95 (should be 2.7)
P7 - 9.02
P8 - 8.30 (should be 0)

I'm 99.9% sure all other components are correct, did a triple check before measuring.  Did I get bamboozled on eBay and get some bad CA3080's?  I tried to look around and find pin measurements on a bad CA3080 but didn't have any luck.  If anyone has that handy, that would be awesome.

I do have one good CA3080 from Small Bear in a working build on the same type of board, but it's not socketed, so unfortunately I can't pull it for testing.  I did measure it for comparison:

IC1
P1= 0
P2= 4.4
P3= 4.4
P4= 0
P5= 0.63
P6= 2.8
P7= 8.9
P8= 0

If it looks like something else is wrong, I'll grab transistor and diode readings and post build docs (this is an Aion board, the Aurora), and I'll start poking around with my audio probe.  Gotta call it quits for tonight, though...pesky day job.

[italianguy63]

I have had much experience with bad CA3080's from eBay (China).  So many that I have quit buying the CAN version altogether.  However, the DIP versions still work.  If you need a CAN CA3080-- you need to try to find some NOS real ones..  not Chinese re-manufactures.  MC

[banjerpickin]

I have had much experience with bad CA3080's from eBay (China).  So many that I have quit buying the CAN version altogether.  However, the DIP versions still work.  If you need a CAN CA3080-- you need to try to find some NOS real ones..  not Chinese re-manufactures.  MC

I'm putting together my monthly Small Bear order, I'll grab another verified one from them, but it's like $5 which stings.  Also this morning I found I had a few LM13700's left over from a previous run, I'll put a socketed daughter board together and see if that works.  They're only $1.50 from Tayda + a little extra installation effort.

[banjerpickin]

The LM13700 fixed the problem instantly and the voltage readings returned to the expected volts.  Built a simple little socketed daughterboard on vero using http://2.bp.blogspot.com/-P7jqffl_ejk/UHVUB0pXl-I/AAAAAAAAC-k/p2HwRW-52S0/s320/LM13700+Daughterboard.png.

Here's a photo of it all wired up on my testing board: http://imgur.com/VyTFXEH

[PaulBass]

just received 5 CA3080 from polida2008 and they all work. They are still pulled chips so don't expect them to be NOS. I think polida2008 has good intentions to make sure all the parts are legit but I don't think they test them. I think the people who got bad ones got legit ones that were broken

[vigilante397]

I was poking around some old parts bins at work and there was one labelled "CA3080," so I got excited and grabbed all of them, only to find out that they were pristine NOS CA3030's