Im trying to repair a schlage handkey which wont boot. I looked at the main board and noticed the chip below. The chip above it is the same part number but when I try to look it up I get nothing. How do I make sense of the markings?

Chip markings

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    \$\begingroup\$ Identification NOT A repair question. \$\endgroup\$ – Passerby Nov 18 '18 at 5:19

This is a standard 74AC32 quad OR gate. The logo is from TI.

The code above is likely a date code or lot code. The code below is the actual part number (74 is implied since its a member of the eternal 7400 series logic family).

Here's the TI datasheet: http://www.ti.com/lit/ds/symlink/sn54ac32.pdf

See page 5 of the datasheet for an explanation of the package markings. This is a SOIC-14 package and thus only contains the letters "AC32".

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  • \$\begingroup\$ nice catch. I was looking at the other number which does look like a standard part code. \$\endgroup\$ – Passerby Nov 18 '18 at 5:06
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    \$\begingroup\$ Hi, To be clear it's not a 54AC32, but can only be a 74AC32. The 54AC32 is (or was - I think it's reached EOL) only available from TI in ceramic packages (their "J", "W" or "FK" packages - see later pages in the datasheet). As you pointed out, this device could be in the SOIC (or IMHO, perhaps the similar SOP) plastic package. Or did I misunderstand and you are really stating that this is a 54AC32? \$\endgroup\$ – SamGibson Nov 18 '18 at 5:13
  • \$\begingroup\$ @sam they mention both parts, and the same datasheet is used for both the ceramic 54 and the plastic 74 parts. The entire part regardless of package is considered obsolete by TI and they are all interchangeable so it doesn't matter if it's a 54 or 74 prefix. \$\endgroup\$ – Passerby Nov 18 '18 at 6:07
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    \$\begingroup\$ @Passerby - Hi, sorry my earlier attempt to explain the problem of stating it's a 54AC32 wasn't clear enough. I'll try to explain better. Stating that the device is a 54AC32 is IMHO misleading because (a) the 54AC32 isn't available from the usual distributors any more (Digikey, Newark/Farnell, Mouser etc.) - the 74AC32 is available. So implying someone should get a 54AC32 is unlikely to be successful; and (b) a 54AC32 won't fit on that PCB, as they were never made in packages that fit that PCB footprint. Therefore IMHO it does matter whether it's a 54 or 74 prefix. See what I mean? \$\endgroup\$ – SamGibson Nov 18 '18 at 15:11
  • \$\begingroup\$ I don't believe its a 54HC32 part either. That was a mistake from earlier and I thought I had reverted all the instances of 54, but I guess I missed a key one :). \$\endgroup\$ – Los Frijoles Nov 19 '18 at 4:28

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