Changed Power Supply - now comp is soooo slow

My computer:
Asus A78NX series mobo
AMD Athlon XP 3000+
1GB ram (2x512)
Nvidia Geforce 7600GS Vid card
333 rated fsb
120GB HDD
250w PSU

This computer is usually very fast, with no wait times on IE for instance, loads everything more or less instantly, and as another example runs warcraft on its highest settings with ease.
The 250w PSU has recently been having problems fan-wise, didn't affect performance, but I guessed this was a good hint that it was on its way out, so yesterday I decided to replace it with a 400w Mercury PSU. I carried out a full system scan with norton before the swap, but didn't bother setting a restore point, couldn't be bothered backing up essential files either (slapped wrist). After I replaced the power supply (I replaced it by unplugging the 4 pin plugs to HDD, CD drives, Vid card, and the 20 pin to the mobo, the FDD plug, etc, didn't touch the data cables etc, then plugged everything back in in exactly the same way, except for the 24-pin mobo plug, which I had to unclip the extra 4 sockets on for my 20pin mobo socket), I booted the computer up. On first boot it seemed to go quite fast to the desktop, slightly slower than usual I seem to recall. Then, when I tried to open different apps, and check the device manager, the computer kept slowing or locking, so I shut down to check the connections to all the components. All the connections were good, so I rebooted. The reboot took about 10 minutes, and basically everything was slowed after this. After about an hour of rebooting, searching the net for possible problems using the working but painfully slow computer, I put the old PSU back.
With the old psu in, it works slightly faster, but is not as it should be. It can run Warcraft for instance, but takes ages to start the game up. IE takes ages to load, and webpages take up to 2 mins to appear. Using windows apps like device manager also takes ages. Booting takes about 5 mins, versus the minute or less it used to take.
I tried to look at the bios to see if any of the components were running at less than optimal levels, but the bios on my mobo won't allow the user to make changes to any frequencies suck as memory or fsb transfer rates. I managed to change the HDD transfer to 32 bit, but that's the only thing I could change.

Does anyone know what might have gone wrong? Is it salvageable, or am I looking at some expensive repairs?

Thanks in advance of any advice.

 

I wouldn't think it is the PSU. Do you have a Floppy drive? If not make sure the BIOS isn't looking for one. Also make sure your HD and CD Rom's are set to Auto Detect in there. Might even try setting the BIOS to best performance or whatever it may be in your BIOS.

 

Hi Lefty,

Thanks for the reply.

I didn't reconnect power to the FDD considering its currently obselete. Could this really be the reason for the lockups etc? Is it worth reconnecting the new psu and seeing if this is the problem?

Edit: tried setting the bios to optimal or best performance, but that wasn't an option

 

So you put the old PSU back in and it still performed not so great....hmm. I wonder if your RAM is going bad....Maybe boot up on 1 stick of RAM at a time and see what happens.

 

Hi Nas,

Thanks for your reply.

Ram is less than a year old, could it go bad that quickly? I'll try that when i get home right after seeing if Lefty's proposal works.

 

I have seen RAM be bad the day you get it in-hand BUT generally in my experience most RAM doesn't go out like that but it could have happened or it may not be all the way gone but going and it could be causing an issue. This way we can sorta start to eliminate that.

 

I ran CPUZ (great, great little component monitoring utility btw if you haven't seen it before) yesterday not long after it happened to ascertain whether or not any components were a bit dodgy. The memory was running fine at that point according to CPUZ, but i guess reseating and trying it out on the different strips won't hurt, so i will try that after work.

 

Did you put the 20pin ATX plug in the 24pin ATX slot? If so, that is your problem.

 

I dont think he did....from what I read the new PSU had 20+4 pin ATX cable and he just made sure he only put in the 20 into the mobo which only is 20 pin? Is that correct Hate Comp?

 

Thanks for replying Maverick. Tell me if this was wrong, i'll clarify what I did:

The new 400w power supply had a 24 pin connector, with a bit you could unclip to make it a 20pin plug effectively. I used that on the 20pin mobo socket.

Do you think may be the problem still?

 

So you are using a 20pin plug on a 20pin socket (minus the 4pins for the plug)? Also, is the 4pin (in a square shape) plugged in to the motherboard?

 

Yup, 20pin on 20pin. The spare 4 pin doesn't have a socket for it on my mobo, that was just flying free in the case before I got myself into this sorry mess in the first place.

 

Right, glad we sorted that out!

I'm actually suprised that your system even booted with a 250W PSU, that's a definate no-no in the technical world, especially considering the GPU you were running on it. But first of all lets get you installed with the software you need for diagnostics, download SpeedFan; http://www.almico.com/sfdownload.php

Once you have downloaded that report back all temperatures and voltages. Also, check on the side of the PSU for what the amperage output is on the 12V rail (signified as 12V) and is usually within a table.

Nick.

 

Cheers Nick,

I'll do that the second I get home this evening, I'm abusing my work internet at the minute lol.

The 250w one was the one that came with the system when I bought it a while back. That's probably why it's now wheezing like an old man...

What do you think about Lefty's suggestion about plugging in the power to the FDD in the meantime? Is that likely to be the cause of the slowness?

 

You're abusing the work internet? I'd hate to think what i'd be classified as doing right now! I'm supposed to be working, but psst, don't tell the boss! By the way, i'm actually not too sure exactly what the FDD is (floppy disk drive or the IDE interface?).