Hi Sam On one of the projects I worked on, we had a lockup problem ( CMOS issue ). It would blow either the VCC or GND lead. We had a wire bonder in the lab. I'd remove the cap from ceramic chips and bond on a new wire. It would work fine until we sequence the power wrong and it would blow wire again. The CMOS technology guy stated they shouldn't do this but it still happened ( simulation vrs real world ). I suspect those parts that have an open lead are bonding wire failures and not silicon failures. If you were setup to install bonding wires, it is technically possible to repair such failures. In a plastic part, that might be more difficult than a ceramic package. Not all failures are bonding wire failures. Dwight
________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Jeffrey S. Worley via cctalk <cctalk@classiccmp.org> Sent: Thursday, July 25, 2019 12:08 PM To: cctalk@classiccmp.org <cctalk@classiccmp.org> Subject: RE: Resurrecting integrated circuits by cooking them. Does this mean that, like me scratching a bit at the package to expose enough nub of broken-off pin to get a blob of solder on to hold a new leg made of wire can theoretically be extended to shaving off the top of the package to expose the IC and then tack soldering the severed wire back onto it? This would probably require some serious equipment I don't have, but sounds possible in extremity. RSVP YHOSvt. ** TNM ** Dwight said: "Message: 6 Date: Thu, 25 Jul 2019 05:52:31 +0000 From: dwight <dkel...@hotmail.com> To: Pete Rittwage <pe...@rittwage.com>, "General Discussion: On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Subject: Re: Resurrecting integrated circuits by cooking them. Message-ID: < byapr01mb5608f4c8a3860c2a7d2bc172a3...@byapr01mb5608.prod.exchangelabs.com > Content-Type: text/plain; charset="us-ascii" "Failure of the POKEY chip were likely bonding wire failures. Voltage stress failures are not likely to self repair. I would agree, the fix is likely temporary. Many early chips used gold wire for bonding but later chips used aluminum. Which is better is always a question. The pads on the die were usually aluminum, while the package was often gold. These are acoustically bonded. One wonders if one put a capacitor on the lead with a non-lethal voltage and used such a heating method, it might be able to arc weld the wire back on. Using the method of heating might enhance the success as well. Dwight"