Have you tried testing the RAM with MemTest86 with the P3 600 present? Couldn't hurt to rule it out.
I also have an P2B system with a P3 600 MHz and 512 MB RAM. My CPU does not use a fan either.

AntiRevisionism wrote on 2021-06-04, 00:39:

Have you tried testing the RAM with MemTest86? I also have an P2B system with a P3 600 MHz and 512 MB RAM. My CPU does not use a fan either.

Thank you for the suggestion. I have not tested the RAM, but it is working for hours with the 550 CPU. I'll swap out the sticks with the 128MB stick that I had and see if that makes a difference.

When I've seen them installed OEM the PII/III is usually in the North/South orientation and the back panel has a 80mm fan sucking air past it. On the P2B it's unfortunately stuck in a nice little valley there, with the chipset adding warmth from below and blocked in by the DIMMs on the other side.

Ergo, I'd do some "arts and crafts" like ziptie an 80mm on top of the whole thing, the above top, not on the tips of the fins.

BitWrangler wrote on 2021-06-04, 00:44:

When I've seen them installed OEM the PII/III is usually in the North/South orientation and the back panel has a 80mm fan sucking air past it. On the P2B it's unfortunately stuck in a nice little valley there, with the chipset adding warmth from below and blocked in by the DIMMs on the other side.

Ergo, I'd do some "arts and crafts" like ziptie an 80mm on top of the whole thing, the above top, not on the tips of the fins.

I may try this, though I'm not sure that the CPU could be getting hot enough to lock up during post. It could be, though that would seem weird to me. I also have the case open while I work on all of these things. I'm waiting for a NOS 120gb IDE HDD to arrive for a slave drive, since the SATA adapter I have keeps giving me a Primary Slave Drive Fail error after every reboot, making me have to power off and then back on. I swear, everything is breaking or simply not working right. It is messed up. It all started when my original 4DPS died a couple of years ago. The replacement 4DPS took me forever to acquire and then forever to get stable as well, and looking at it wrong means I have to pull the RAM and reseat it. These situations are becoming ridiculous. I am worried that when I get an AWE64 Legacy, my house will burn down after I install it and fire up the PC...

Agree ! many OEM like Compaq did the huge heatsink w/o fan because the OEM case layout and fans were designed to force airflow a certain way (usually up and out <but not always>).
When used in a standard case the airflow will not be the same because airflow is generally front to back, but cpu HS feeling warm is common. Adding a small heatsink fan is a good idea.
I suggest you pull the CPU and clean the edge contacts with ISO alcohol on qtips/swabs/etc then rig a fan on it. And do run MemTest86.
What BIOS version are you using on that P2B rev 1.04 ? Just curious...

Horun wrote on 2021-06-04, 01:05:

Agree ! many OEM like Compaq did the huge heatsink w/o fan because the OEM case layout and fans were designed to force airflow a […]
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Agree ! many OEM like Compaq did the huge heatsink w/o fan because the OEM case layout and fans were designed to force airflow a certain way (usually up and out <but not always>).
When used in a standard case the airflow will not be the same because airflow is generally front to back, but cpu HS feeling warm is common. Adding a small heatsink fan is a good idea.
I suggest you pull the CPU and clean the edge contacts with ISO alcohol on qtips/swabs/etc then rig a fan on it. And do run MemTest86.
What BIOS version are you using on that P2B rev 1.04 ? Just curious...

I am running the latest beta bios. I originally installed it to get 128gb support. I considered the contact cleaning, though they look very clean. You never know, though.

I tried swapping out RAM sticks, and I positioned a large, high RPM fan next to the heatsink, as after a few minutes the heatsink was quite hot to the touch. This kept it very cool. However, I couldn't boot into Windows on either of my Win9x SD cards. I tried another 128gb SD card in my CF-SD-IDE adapter set up, and attempted to install Windows to that and kept getting kernel and other errors. I am diagnosing this CPU as faulty and messaged the dude on Mercari, and am waiting to see what he says. It was the cheapest compatible 600Mhz P3 I could find, and I may give up on it as it is only 50Mhz faster, and with random stability issues - I am wondering if this P2B is needing recapped or if I should just look for a socket 370 CPU/Mobo combo and get something faster, newer, and more stable. I just want to play some games on a working system with a working 19" CRT, but things just keep happening.

Hmmm, I am just noticing that that's about the highest wattage slot 1 CPU you can get, being top end of the Katmai cores. Maybe components, probably caps are getting a bit marginal with age.

BitWrangler wrote on 2021-06-05, 22:15:

Hmmm, I am just noticing that that's about the highest wattage slot 1 CPU you can get, being top end of the Katmai cores. Maybe components, probably caps are getting a bit marginal with age.

I am committing to learning how to desolder/solder because of all of these things that are happening to me and my components. I'm grabbing extra motherboards, CPUs, and 17" and 19" CRT monitors. I'm going to buy some learning kits and some equipment and testers, and look at Udemy to see if there are electronics repair classes.

My house was recently rewired (mostly done, I'm getting some exterior work done in a few days,) and I had my dirt basement floors leveled, tamped, and had plastic and plywood put down. I am going to install a grid of flat LED strips across the entire basement ceiling. We are going to paint the entire basement with white anti-mold primer, and I had an exhaust fan and vent installed. The one room is being turned into my new workshop (one side if for wood, the other side is for computers and electronics, and one corner is getting set up with a kiln and a microtool station.)

I think I will set up a soldering station under the exhaust vent and next to the microtool setup. I'll set up a laptop with internet for research/learning/how-to's, and after going through the exercises in 2-5 different learn-to-solder kits, I'll practice removing parts from some old crappy mobos I have, and will tinker with that old (I think 14") monitor. I don't want to buy multiple CRT monitors, motherboards, CPUs, and Voodoo 5s for the rest of my life (and spend a fortune!) I think that if I'm going to maintain this very-important-to-me hobby, I need to learn how to maintain these items. I decided to take my NOS KDS to a technician in a nearby city (about a 1.3 hour drive) because it is too nice for an amateur such as myself to mess with it. However, I will tinker with the little monitor and that dim Gateway I have. As far as this CPU, it could be a power issue with the mobo caps, or it could be a faulty CPU. If I find a cheap replacement, I'll probably grab it, though I am definitely going to look at some 370 P3 mobo/cpu combos. I may even get lucky and find a 1.4 GHz Tualatin and build an absolutely maxxed out P3. But learning to work on these parts is a must, at this point.