Pretty sure that is a capacitor, not a resistor.

My bet is a zener diode. Can you make a better photo of the actual part? Or write down what the markings are, I could tell you what to replace it with.

Deunan wrote:

My bet is a zener diode. Can you make a better photo of the actual part? Or write down what the markings are, I could tell you what to replace it with.

The component itself has "A3Z3" on it. I can take a better picture when home but my wife's eyes are better than mine (and the board right here in the car as I went to an electronics supply shop who had no idea) but my phone camera isn't great. There are other ones on the board too, all with A3Z3 on them.

Thank you guys. 😀

Deunan wrote:

My bet is a zener diode. Can you make a better photo of the actual part? Or write down what the markings are, I could tell you what to replace it with.

I think this picture is a little bit better. I hope it's able to help. 😀

cyclone3d wrote:

Pretty sure that is a capacitor, not a resistor.

I'm going down this route at the same time, to see if I can narrow things down. MLCC capacitor? I dunno. I'm just so stumped as A3Z3 doesn't really come up with much of anything. 🙁

That looks like a axial ceramic capacitor, probably a 0.1µF that litters old mobos.

I don't know the capacity you need, but the second picture with this ebay offer has some explanation with it.
https://www.ebay.nl/itm/100x-AVX-axial-100nf- … =item5b218f9492

Hope it helps

Thallanor wrote:

The component itself has "A3Z3" on it. I can take a better picture when home but my wife's eyes are better than mine (and the board right here in the car as I went to an electronics supply shop who had no idea) but my phone camera isn't great. There are other ones on the board too, all with A3Z3 on them.

Ah, if all of them have the same markings then a zener diode is unlikely. Can you make a photo of some of these other A3Z3s then? That 3-pin part, is it a power transistor or a 78xx/79xx voltage regulator?

You guys nailed it! Axial capacitor. Unfortunately, electronics supply shops are going the way of the dodo here so I couldn't find a ceramic capacitor replacement. In fact, I couldn't even find anything closer than 0.47uF @ 250V. I bought a couple and tried my hand at soldering for the first time in 25 years. At least managed to find my old leaded solder. 😁 Butchered the soldering job but did manage to get it in there. And then had a friend point out that based on the transistor, I likely have the polarity backwards. D'oh. But it works - just the capacitor is likely going to let out its smoke prematurely. I went ahead and ordered an assorted 500 pc kit of ceramic capacitors from Amazon for $23 and they should be here Thursday. I'll swap out the capacitor then, since polarity doesn't matter with ceramic capacitors, to the best of my knowledge. In the meantime, it works! Just fun typing on this keyboard without keys right now, until I get the foam replacement kits. But it works!

Good thing this picture is out of focus. It hides my horrible soldering skills. 😀

Deunan wrote:

Ah, if all of them have the same markings then a zener diode is unlikely. Can you make a photo of some of these other A3Z3s then? That 3-pin part, is it a power transistor or a 78xx/79xx voltage regulator?

When I carefully lifted it, it was a 78xx. I checked for a friend because he was attempting to determine if I botched the polarity when I soldered in the capacitor. 😀

My assumption was a zener + power transistor but if that's a 78xx series regulator then the capacitor is 10-100nF non-inductive one to prevent the part from self-oscillating. That's always a risk with any sort of feedback. The cap has to be close to the regulator (and it is) and the "non-inductive" part means it can't be an electrolytic or any other foil-based kind. A cheap disc ceramic will do nicely though - the axial ones are usually higher quality but it's not critical here.

Deunan wrote:

My assumption was a zener + power transistor but if that's a 78xx series regulator then the capacitor is 10-100nF non-inductive one to prevent the part from self-oscillating. That's always a risk with any sort of feedback. The cap has to be close to the regulator (and it is) and the "non-inductive" part means it can't be an electrolytic or any other foil-based kind. A cheap disc ceramic will do nicely though - the axial ones are usually higher quality but it's not critical here.

That makes sense. I should be receiving my order of 500 0.1uF to 10uF ceramic capacitors tomorrow so I'll replace it then. 😀 In the meantime, I'll continue to use it and just be aware it might give up its magic smoke sooner than later. 😀

I appreciate everyone's suggestions here. I'm giddy that the keyboard lives and that I can use it (awkwardly, without keys) by tapping at it, so I can at least use the computer a little bit. 😀