Sob

[Marcovecchio]

(07-12-2022 06:36 AM)teenix Wrote:  I was just removing a ROM 0 chip to read. I had it all unsoldered and was loose, but as I was pulling it out with just a little pressure and the case just crumbled and 7 pins broke off - from a HP-92 to make things worse :-(

Oh my, sorry to hear that..

I'm not sure, but it seems to be an epoxi case, and these can absorb humidity from the air. And when this happens, and the IC is heated, water will expand and potentially create micro fractures in the epoxi.

That's why components are "pre baked" before soldered in soldering ovens, to evaporate the water before the higher soldering temperatures hit the part. It's a long shot, but may be one of the possible causes!

Also, there's a small possibility to save the IC, by using a rotary tool with a suitable bit to eat away enough epoxi to expose what's left of the legs. The you can plug the chip in a regular IC socket, and then plug the loose leads to the same socket, just to hold everything in place, so you can try resoldering the legs back. And then, if all that works well, use some epoxi adhesive to mechanically reinforce the joints. It's a lot of work, but I managed to do that on some rare ICs from old 8 bit computers.

Eduardo