Bad power supply?

[Scouzer]

Okay, so I have this old ECS K7S5A that has been sitting for ages with an old T-bird 1.4ghz. I dug up a generic 300W PSU, and see if I can power it up with nothing installed, see if anything will work. So I plug it up, and press power, CPU fan does one rotation and everything stops. Same thing everytime.

Bad PSU? I tried just now with a PIII800E and Asus P3V4X, fan spun up fine and it seemed to work. Is it because the Athlon chugs too much power and the PSU can't cut it? Keeping in mind both of these computers ONLY had CPU's and memory plugged in.

 

[Scouzer]

So I tested it on my good PSU, and sure enough it spins up, but there's a catch. It fvcking started smoking!! I immediately shut off the power and I have no idea WTF was smoking. It was near the PSU, but it wasn't the CPU.

 

[mechBgon]

Do you recall whether the K7S5A and/or TBird got sidelined for any particular reason? An anemic PSU might not have what it takes, that chip rivals any of AMD's current ones for power drain (no pun intended) and the K7S5A powers it from the 5V rail so it earned a reputation for not liking so-so power supplies. The P3 800 pulls a little more than 1/3 the power of the TBird 1.4GHz, around 25W maximum.

 

[mechBgon]

Originally posted by: Scouzer
So I tested it on my good PSU, and sure enough it spins up, but there's a catch. It fvcking started smoking!! I immediately shut off the power and I have no idea WTF was smoking. It was near the PSU, but it wasn't the CPU.

:Q !

Pull your ATX cable and check it for burns on the contacts.

 

[mechBgon]

Oh, and also make sure your heatsink's set up like this: pic and that you're (duh) using thermal grease between the CPU core and the heatsink

 

[Scouzer]

Originally posted by: mechBgon

Originally posted by: Scouzer
So I tested it on my good PSU, and sure enough it spins up, but there's a catch. It fvcking started smoking!! I immediately shut off the power and I have no idea WTF was smoking. It was near the PSU, but it wasn't the CPU.

:Q !

Pull your ATX cable and check it for burns on the contacts.

I'm on the good computer using the PSU now. The PSU is fine. I have no idea what was burning on the board. It was extremely dusty with a bit of cat hair, maybe that's all...I'm hesitant to try again though for obvious reasons.

The fan is set up like that

 

[mechBgon]

Hmm, it does make you wonder. One of the things that can cause a PSU to simply power off is a short. For instance, if there's a Molex that manages to land a 5V or 12V pin on a part of the case, the PSU will usually shut off right away. There isn't a stray screw jammed among the mobo's bits and pieces or anything...?

 

[Scouzer]

Well, I found a tiny tiny screw that was hidden behind a capacitor not far from the smoking site. Could this be the culprit?

Wow. I hadn't even read your post and I discovered the screw, you read my mind. Would it be safe to try again?

 

[mechBgon]

Hehe, I dunno, ask your Magic 8-Ball

edit: and no, I can't read your mind. I'm simply spying on you through your optical mouse :evil:

 

[Scouzer]

Hehe, I tried again on old PSU, same story. I guess I'll try on my good PSU one time before I send these parts to the grave.


Aaannd nothing. I guess I'll sell off this CPU 'as is' and chuck the mobo.