That cpu is likely deep sixed.

That's what I thought at first, but it doesn't make sense that a CPU that worked perfectly five days ago would suddenly die. I didn't even touch it until today. Plus, I did some research and found out that the motherboard is supposed to give you some warning beeps even if the CPU is missing (I could be totally wrong on that, however). It's far from improbable though that it is the CPU... 😵

Running it with no hs/fan on the cpu even for a few seconds can kill the CPU. I'd bet it is dead.

Yea some Athlon XP chips have no heat protection built in. On newer CPUs they will throttle and then turn the system off, Just test with another CPU?

https://www.youtube.com/watch?v=UoXRHexGIok
This probably happened 😜

By golly, you are exactly right- that is precisely what happened. In fact, I thought I smelled smoke for a little bit there but I thought it was just my imagination...

Unfortunately that was my only CPU in that form factor, so I'll have to mooch one off of a friend or buy a cheap one on eBay just to test this MB. Darn.

Is the MB likely shot too or just the CPU?

And now this has got me worried about cooling on my pentium box. Does a pentium/100 need a heat sink? Right now I just have a fan jerry-rigged onto it and it seems to be doing fine, but should I be worried about it overheating?

Now, what about the other MB I mentioned? It's an old AT type Socket 7 board. I've tested it with known working CPUs and still nothing, just the fans run and no beeps (although I don't think it actually has a beeper; I'll have to hook one up). What is likely to be wrong with this one? Thanks for all your help by the way; don't know where I'd be without you guys! 😀

MrEWhite wrote:

https://www.youtube.com/watch?v=UoXRHexGIok
This probably happened 😜

That video newer gets old.

Tom's hardware was THE site back in the day. They did things nobody else would look into, often uncovering mayor issues and faults 😀

PhilsComputerLab wrote:

MrEWhite wrote:

https://www.youtube.com/watch?v=UoXRHexGIok
This probably happened 😜

That video newer gets old.

Tom's hardware was THE site back in the day. They did things nobody else would look into, often uncovering mayor issues and faults 😀

Gotta love that music. Epic video

PhilsComputerLab wrote:

Yea some Athlon XP chips have no heat protection built in. On newer CPUs they will throttle and then turn the system off, Just test with another CPU?

Incorrect. Every AMD CPU after the T-Bird era had a thermal diode installed for temperature monitoring which motherboards were to use for detecting thermal trips. The actual problem had two potential sources: motherboards without support included as they predated the thermal diode, or improperly implemented support on new boards.

How?

That's what I said, the CPU does not have protection built in to protect itself. It has to rely on the motherboard, which is weak protection. Later AMD chips have built-in protection.

Well, I don't know what Athlon it was. Not an Athlon XP, that much I know.

What do you guys think about the other motherboard I mentioned in the OP? It's a VIA chipset, old AT form factor, and has exactly the same problem except I've tested it with known working CPUs and the same thing happens (fans run, but no video or beeps). I replaced all of the bad capacitors but still no luck. The jumpers are all set correctly. Is this board dead or am I just doing something wrong? I'd really like to get it working since it's the AT board I have which has an AGP slot; otherwise I'll have to get a PCI video card for the other one which doesn't have AGP.

I see what you're saying. Yes, the P4 solution was more robust. For AMD, higher integration was the answer to motherboard support issues (although they didn't use throttling, just shut down).

The T-Bird era processors truly had no thermal protection, as they had no method of monitoring die temperature directly.

As for the Socket 7 AT board, running fans don't tell you much as far as function. Lots of stuff could be cactus including the chipset, the BIOS chip, CPU, etc. You'll have to isolate the problem as much as possible.

Well, at least I know it isn't the CPU: I'm using it in my pentium box right now. And I tried a different BIOS chip; it still didn't work. Maybe it is the chipset and I wasted the $4.00 I spent on it... although I'm still hoping it's just something I'm doing wrong. There is a chip on it that looks kind of like a voltage regulator except the middle pin is cut off, which I do see a lot on MBs, but this one appears to have been either soldered on wrong at the factory or forcibly pushed off its surface-mount solder pads so that the leads are hanging off the edge of the PCB. (warning, stupid question ahead)...Could this be an issue?

Could this be an issue? Yes, physical damage is always suspect.

I wouldn't be surprised, you could try to bodge it (messy solder job) and go from there.

I can not say if it's one thing or the other without a picture of the Socket-7 motherboard in question, some boards have really really shoddy soldering but works as they should anyway.

PhilsComputerLab wrote:

MrEWhite wrote:

https://www.youtube.com/watch?v=UoXRHexGIok
This probably happened 😜

That video newer gets old.

Tom's hardware was THE site back in the day. They did things nobody else would look into, often uncovering mayor issues and faults 😀

Pentium 3 1133 anyone?

Probably messed up the socket.

OK, here's a picture of that Socket 7 board:
EDIT: When you zoom in the bad component is near the lower right... 😒