Atari 400 TC4051BP Chip Question

[gobo]

Hey Guys, I bought another Atari 400 a little while back for the forthcoming 400 Incognito. I finally got around to testing it and it boots carts fine. Has a clean picture but there is no sound or keyboard functionality. When I opened it up both of the TC4051BP chips were missing. I ordered chips off of ebay today titled "TC4051BP "Original" Toshiba 16P DIP CMOS IC 2 pcs" for a few bucks. Are these chips interchangeable? Just wanted to make sure before I try them out. Other than the missing chips it looks very clean inside and out. Thanks!

 

These are the actual chips from ebay:

[+Nezgar]

Should be fine. Keyboard matrix decoder chips.

 

Same ones used in all the XE / XL's too.

[gobo]

Thanks. The machine is like new inside other than the chips. Strange.

[+DrVenkman]

Yeah, 4051 chips are standard, off the shelf logic chips. Still made today and still fully compatible with vintage. I had several of them that were bad in a 5200 I bought off eBay about 4 years ago. I bought a set of brand new Texas Instruments 4051 chips (from Mouser or Digi-Key, can't remember which) and replaced the dead originals. No sweat.