Maybe through the chip implementation standard (but I've not been able to find that documentation):

UMC
UM61 3233F-7
9628SE B6501

Might work without it. I believe that is for the cache chip voltage stabilization. You can see a similar unlabeled capacitor on the chip below it. You can probably just install a 1uF cap and it will be fine.

yeah - you make sense!
I did try to look around the other chip but the "shape" of how things are laid out is different and I gave up...
However, screw the layout! Look at the actual pins!

I am thinking to remove the SMD that looks good on the other chip and measure that...

Do you suppose these can be replaced with through-hole ceramic caps?

You could try to ghetto mount one, but it is recommended to use a SMD cap. They look to be 0805 size, so it is just about as easy to solder as a through hole component.

Follow this method for soldering a surface mount passive that size: https://youtu.be/PU7wLcuqc-I

DraxDomax wrote on 2021-07-03, 19:07:

Do you suppose these can be replaced with through-hole ceramic caps?

If these caps are for voltage stabilization ("bypass caps"), they are usually 100nF multi-layer ceramic capacitors. SMD capacitors are slightly more effective, because the leads of the through-hole capacitor put it further away from the circuit (board) than an SMD cap. If you solder a 100nF through-hole capacitor there with minimal lead length, it should work fine, too.

Ah, 100nF (0.1uF) is correct. Off by an order of magnitude. :p

I took the good one off, from the other IC.
According to my tester, it's 130nf.

Unfortunately, in my little baggy of SMDs, there are not a lot of caps... 47 and 300 somthing... And I'd rather not build some network to get an equivalent 😀
Can barely see how to solder the good one back! 😁

I am going to measure and install a through-hole ceramic capacitor. Will keep the legs as short as possible...
Before testing, will check here in case someone says "nooo don't do that!" 😉

I mean the weird thing is that the first time I measured it, it was 150nf.
But 10 measurements after that, all showed 130nf... Maybe it was the heat from desoldering...
On the other hand, 130nf doesn't sound like a standard size...

Oh well!

DraxDomax wrote on 2021-07-03, 22:03:

I mean the weird thing is that the first time I measured it, it was 150nf.
But 10 measurements after that, all showed 130nf... Maybe it was the heat from desoldering...
On the other hand, 130nf doesn't sound like a standard size...

It's extremely likely a standard 100nF cap. Every uses 100nF caps for that purpose since the early 80s. Don't worry about exact capacity. You might be right that heat influences the capacity, also the wiring from the cap to the meter might do so. The exact capacity doesn't matter, though. 47nF or 220nF would also work good enough at that position. 100nF is just a convention.