A dumb question about a chip

Orion7319

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So I have a socketed chip that I noticed has a leg broken off of it. It's a SN747LS626N. Of course I can't find one of these, but it looks like arcadepartsandrepair has a SN74LS629N. The specs look the same so I am assuming I can just get one of these and be fine. I don't know enough about electronics to know for sure though so I thought I would ask. Why do these old chips obsolescence and why do they replace them with newer chips that seem to be the same speck wise? What's the deal with that.... curious minds want to know....

https://www.mouser.pr/ProductDetail/Texas-Instruments/SN74LS626N/?qs=4FFjqLL55bRN2qgRYTlU0w==

https://www.mouser.pr/ProductDetail...GAEpiMZZMukHu%2bjC5l7Yep1wH0ZStxMqlrOVcLfppc=

https://www.arcadepartsandrepair.com/store/components/74ls629/
 
have you searched ebay? they sell everything there!

anyways, i would not recommend replacing an IC with another IC... looking at the data
spec sheets, the pinouts are different between the 626 and 629, as such:

626.jpg
vs
629.jpg


626vs629.jpg


i've attached the pdf data specsheet to this post, it covers both the 626 and 629 in it...

yer better off replacing the 626 with a 326 as the above chart suggests!
 

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have you searched ebay? they sell everything there!

anyways, i would not recommend replacing an IC with another IC... looking at the data
spec sheets, the pinouts are different between the 626 and 629, as such:

626.jpg
vs
629.jpg


626vs629.jpg


i've attached the pdf data specsheet to this post, it covers both the 626 and 629 in it...

yer better off replacing the 626 with a 326 as the above chart suggests!


Thanks! I'm glad I asked! Yes eBay has them, but only from one seller in Israel it looks like. Didnt want to wait that long, but I suppose that's what I'll have to do. I might try and find an LS326 in the meantime. What's the difference in those though? Thanks again!
 
Last edited:
https://www.ebay.com/itm/1x-TEXAS-I...202297?hash=item2a6f603479:g:f-QAAOSwsB9V-qeo

You might want to carefully dremel above the broken leg so you can use a touch of solder to add a wire or a leg from a donor chip to fix your chip.

https://forums.arcade-museum.com/showthread.php?t=262439

https://www.electronicplus.com/search-return.asp?search=package

Thanks! I ordered that one on eBay. I soldered a wire on the leg and it's working but it seems rather flimsy. I suppose it will hold until the new chip arrives.
 
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