xbit wrote on 2023-02-24, 00:42:

Any idea what this small heat sink is cooling? And I'm wondering if its supposed to get as hot as it does. Like VERY hot. I almost want to put some thermal paste and a tiny fan on it <g>

It converts supplied 5 Volt to 3,x Volt for the processor, when configured to do so. It is the voltage regulator.
On both my 486 motherboards I added a slighly larger heatsink to this VRM, to lower the temperature slightly. But such modifications may interfere with larger add-in cards in the nearby slots.

Thank you. One thing I noticed is it bends very easy. So, something to be carful with i'm sure.

>what this small heat sink is cooling?

linear regulator

> And I'm wondering if its supposed to get as hot as it does. Like VERY hot.

Yes. Linear regulators are, to put it simply, just resistors radiating away the input/output difference (dropped voltage). Very inefficient as you can imagine. Whatever the power 3V CPU uses that regulator will eat additional ~50% while being significantly smaller.

> I almost want to put some thermal paste and a tiny fan on it

do you have the urge to mount additional radiators in your car? or modify the thermostat? after all coolant easily hits 100C! 😀
Linear regulators are designed to operate at those temperatures just fine. Dont worry about it.

>One thing I noticed is it bends very easy. So, something to be carful with i'm sure.

yes, dont bend it 😜 Ideally radiator should have its own leg or lie flat on the side. Looking at https://theretroweb.com/motherboards/s/lucky- … r-ls-486e-rev:d Lucky Star went that route in later revision. Of course this would only matter in mobile applications where constant movement has a potential of stressing the part beyond its limits - this is why big capacitors (heavy part on small two legs) tend to be glued down with white snot in power supplies.

Thank you all for the info! I've learned things 😁