Hi all,

I’ve had my HP Pavilion, running Win 98, I believe it’s a Pentium II, for about 2 years. For the past year we’ve noticed a gradually increase in the amount of noise it makes when running. The past week it’s gotten really bad: there’s a grinding sound when we first switch it on, then it settles down to a noise like a tractor motor.

From the online reading I’ve done, it sounds like the most likely culprits are the power supply fan or the CPU fan. How would I distinguish between these two? Is there another possible cause that I’m overlooking? Would either of these repairs be something that a semi-novice could tackle? (I’ve been “inside the box” to add memory and such, but this would be the biggest repair I’ve attempted.)

Thanks for any help!

Gretchen

First Place I would check is the CPU fan.
Open the case (with the Unit turned OFF) and look at the fan.
Then Boot the system and listen. You may be able to hear what fan is the culprit.
Shut the system down .
Look for dirt and dust build up on the fan blades and the heat sink.

If you have a can of compressed air use it to blow the dirt/dust out of the fan and H/S.
Also Look at the back of the power supply ( Vent Holes) for the same build up.

Use a vacuum cleaner to pull the dust out of power supply. ( Don’t blow it inward)

Then with the case still open Boot up the system and listen for the sound again.

If the sound is coming from the CPU fan and you have a PII it isn’t that hard to replace the H/S and fan.
It is held in place by two clips on the top of the H/S. Release the clip.
When you remove it
It should have small alignment pins near the center of the H/S
Clean off any H/S paste from the chip.
Then install a new H/S and Fan

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To ERR is HUMAN
To REALLY screw things UP, YOU NEED a COMPUTER !

Thanks, Rick!

I tried your suggestion of booting up with the case off. Unfortunately due to the way the unit is configured, I’m still not sure where the sound is coming from! This is a tower model (a Pavilion 8570C, to be specific) and so if you can picture this: when I take the left side of the case off and look in from that side, I see: top left and towards me, the power supply; top right, the various CD/floppy drives; bottom left, away from me, the PCI card slots, so I’m deducing that the CPU must be back there behind the power supply, where I can’t see it! (Is my deduction correct?)

In any case, the point is the two fans are close together and one behind the other so it’s hard to tell which one is making the noise. I did try feeling the back of the case during bootup and the left hand (power supply) side seemed to be vibrating more than the right. Also it is just such a loud, deep sound I have trouble believing it could be coming from the CPU fan. (I think they are smaller, right? I still haven’t seen mine!) This is frustrating b/c I’m sure if I had a knowledgable person here in this room they’d know immediately!

Oh one other thing I forgot to mention in my first post: the day that this problem first became acute, one day last week, we had had the computer on for several hours (like all day), shut it down and soon after tried to reboot and got an error, “Operating system not found.” Waited till the next morning and it started up fine (and has every time since – we’ve avoided keeping it switched on whenever possible!) Anyway since the problem went away after a literal “cooling off” period, I thought it could be a symptom of overheating. Does that make it more likely to be one fan vs. the other?

A related question, I read somewhere (prob. elsewhere on this site) that the more “advanced” chips (Pentium 3 was mentioned) will slow themselves down if they’re overheating. Does this apply to Pentium 2? (I confirmed that’s what we have.)

If I do have to replace the power supply, any advice on finding a retailer? I want to find a local retailer in the NYC area – I’ll see if HP can refer me, but just wondering if anyone has any recos.

Sorry for rambling and thanks again,

Gretchen

I worked on a machine like this once and yes, the cpu is buried well. If I had to bet, I would say your cpu fan is hitting a cable. In any case, you're going to have to locate your fan. You can do it, after all, it's a very small case. http://www.PCGuide.com/ubb/smile.gif

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Give a man a fish, and you feed him for a day. Teach him to use the net, and he wont bother you for weeks.

Whatever you do don't go through HP for a new one...they will charge way too much. If it is the CPU fan try a search on someplace like Pricewatch (http://www.pricewatch) or Pricecombat (http://www.pricecombat.com./) you can find PSUs there also...just make sure you have the specs for it. Also you can check out here (http://clubs.yahoo.com/clubs/hppavilionsupport?s), as some one may the specs for the psu...

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mjc
Links list:Computer Links (http://www.dreamwater.org/tech/mjc/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.

I get this strange feeling the Hard Drive also needs to be checked.

Luck.

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......Indecision may or may not be my problem......
...... Kickin' A Rock....