Old computer noisy, CPU fan spins up

[mikepukmel]

I have a 11 year old Dell E510 computer. Was OK for what I need (post on the blogs etc).

A few years back, the CPU fan started going wild under load. I took it apart, pulled the CPU heat sink of, cleaned it off and put some new heat sink grease and it was better for a while (year or so?)

Recently, maybe a year, when its under load, the CPU fan goes to max, and the computer slows to a crawl. Since its WinXP, I can't find any software that will read the actual CPU temps.

I pulled it apart again, really cleaned the cpu case and heat sink, put new heat sink grease on again thinking I screwed up the last time, and this time no improvement.

Its like running on half a CPU. Tried a different hard drive I had setup with Win7 (clean drive), thinking maybe a virus or some other crap software was causing the problem, same thing.

The fan noise is awful, but the CPU spikes and everything slows to a crawl.

Anyone run into this?

Thanks!!

[Enzo]

Have you tried just replacing the little fan?

[big_teee]

Do what I do, and give it to some kid, and buy a new cheapie!
I give my laptops away, or they get viking funerals, every 3-5 years!
T

[g1]

My fan started working a lot harder and I noticed similar slowdown issues. In my case, recapping the power supply made a huge difference.

[bob p]

I've dicked around with caps on old PC more than I care to admit. I've replaced caps on the PSU, on cards, and on motherboards. In every case I think I would have been better off punting, just because time is so valuable and PC components are so inexpensive today, and because so little computing power is required to do simple office type tasks. Now I just keep spares on the shelf. I also keep boxes of old PC parts on-hand for diagnostic purposes. (like old PWM CPU fans)


Modern systems are designed to monitor CPU temperature and throttle the CPU speed. Although you may not have an XP user interface to monitor the CPU temp, the BIOS and OS are probably doing that behind the scenes. All current systems should have this feature built-in. Check your BIOS to be sure. Many PC BIOS have health monitoring screens that show you system temps and fan speeds.

CPU fans are notoriously cheap items that are overpriced. They fail all the time. If you own any PC long enough then you'll have a CPU fan failure. I replace them ... a lot.

From a diagnostic standpoint:

Checking the CPU thermal junction is a good idea, but it's unlikely to be a problem if you've already verified that there's adequate heat sinking in place. Silicone grease doesn't evaporate. Once you put it there it stays put.

If the fan is slow and won't spin up to speed then you're probably looking at a worn out fan. Sleeve bearing failure leads to low fan speed and seizure.

If the fan is pulsing up to full speed then the bearings are probably OK and the fan is capable of working at speed. The 12V rail to the fan could be malfunctioning. That could be anything from a PSU rail problem to a local PWM control problem on the motherboard.

IME a PC won't run properly if the 12V rail isn't solid. Usually when the PSU goes bad the PC won't even boot the OS. If you're loading the OS and thermal throttling is working then chances are that the PSU is providing a solid rail, as the PC won't work without one. At that point I'd look at the fan PWM circuit on the motherboard. If it is bad then you're looking at an upgrade.

Look at the pinouts on your CPU fan, One wire controls the PWM signal, and if you interrupt that one and only that one then the fan should run at full speed like a 3-wire fan.

1. Try testing the CPU fan (4-wire PWM fan) on a PWM header on a different PC to confirm that the fan works properly.
2. Try testing another 4-wire PWM fan on the motherboard's CPU fan header to verify that the CPU fan header PWM control circuit is functioning properly.
Chances are one of these two tests will fail and give you the answer.

If the PWM control on the motherboard is failing then you need a new motherboard. Chances are that you could disconnect the PWM control signal on your CPU fan, converting it from 4-wire PWM control to 3-wire full speed, but that's a band-aid solution at best.

[Enzo]

I hate working on computers, but I have had to replace any number of CPU fans over the years. Then I started stocking them when I discovered that was what was in some of the MArshall AVT series, and they were failing there too. Wound up with a bunch of heat sinks I had no real use for.

If my computer needs something other than a CPU fan, a power supply fan, or a new power supply, I am not likely to bother.

[g1]

In my case, the computer was getting slower with higher demands like youtube (and windows updates ), which made the fan run much more and I could hear it.
One day it just quit. I had a spare NOS supply and swapped it in, which got it running again. That prompted me to look in the old supply where I saw several bulged caps so I just replaced most of them. The bigger high voltage ones checked out fine so I left them. Once I reinstalled the repaired supply I no longer had speed issues and the fan ran much less often.

[Brad1]

Late 90's/early-2000's, electronics were saturated with bogus bad caps, mainly from counterfeiters. Those things were in and on EVERYTHING, especially from overseas. I've replaced literally MANY thousands of them at a previous job, and in my own stuff. And, they can slow things down, though it still appears to work, and lock things up intermittently.

Anyway. About the heat sink compound. I have repaired repairs done by other techs at my workplace, and thought it was silly that I had to finally have this mentioned at a department meeting. "No...if a little is good, a LOT is NOT better!" Too much can actually create an insulating barrier between the cpu and heat sink, which defeats the purpose. The heat won't transfer as well, and the CPU will run hotter and start bugging out. That stuff is supposed to be spread on thinly and evenly. And, it does no good to have to clean up the mess of goo squirting out the sides when locking the CPU down, anyway. (Or, just leave the mess for the next tech to spend an extra 10-15 minutes cleaning up and drying out!!)

Just get a new fan. Another thing that we found that was making caps go bad was not bad caps, themselves. It was stopped, stuttering or slow fans that apparently stressed out caps on motherboards. At that previous job, they were using specialized (and VERY expensive) motherboards that slotted into a backplane. Before I started working on those particular units, when those came in with blown caps, they'd just replace the board. But, I noticed that all the ones that had bulging, leaking caps ALSO had wonky CPU fans. I suggested trying to replace all the electrolytics (11 of them), and installing new fans. We had a very high success rate of saving those boards, and getting them back out to keep the customer running. Any of them with the repaired boards that came back since repaired, were for something other than the boards. It was mandatory to install new fans on each unit, even if it had only been out a few months, and came back because it was dropped, or something. Finally, if a board did NOT work after repair, or was otherwise toast, it then got replaced. But, they ran out of those exact revision of boards. The new revision was different enough that they had to spend a LOT of time and money to set it up and test it in the ultra-complicated system rack full of everything connected to it. How many went to scrap, that could have been saved, and avoided a new rev board, (or at least bought a few more years to plan)?

Anyway, I have old computers, myself. I still use my main MIDI computer, an old PIII running Win98. Why? Because it still works for MIDI with Cakewalk 6, and the BiPort 2x4s MIDI interface, as well as other stuff I am used to for composing. There's no great demands with only MIDI. And, once I have my compositions "arranged" and am ready to add audio, IT follows (slaves from) my audio computer (as master) flawlessly. Why change? I even have a duplicate motherboard, RAM, CPU, cloned hard drive and power supply, should any of those fail.

Anyway, if you wish to keep using it, and you KNOW the fan is bad...just order a new, inexpensive fan. Apply heat sink compound properly. Carefully inspect all the electrolytic caps for bulging, and oozing brown spuge. CLEAN the board well. (Dust can be conductive, and cause weirdness.)

Just do what makes the most sense!

Brad1

[mikepukmel]

Thanks everyone, read all your posts and suggestions. The fan doesn't pulse, it spins up to what I think is 100% speed. Really fast and loud. Sits there for a while, sometimes minutes, sometimes won't spin down unless I stop some process. I don't ever remember having a computer that spun the fan up on high CPU usage unless it was like 90 degrees in my little office.

I did clean and re-apply heat sink compound but possibly (likely) screwed up with too much grease.

Bob, hmmm PWM on the motherboard, don't have a scope but have two older computers both Dells, that might be able to swap the fan between them, will try that.

Also, looking for where to check the 12v is actually a solid 12v. Eek, now that you mention it I have replaced the power supply in Dell #2 (this one is #3) 2 times. The first time it went, I was sitting in my creaky office chair, turned on the switch on the surge protector, and the power supply spit out smoke, and threw SPARKS out the back and lit up the room (its usually very dark in here, only a small window). Scared the cr@p out of me. Never had a computer PS go like that. The second one, just stopped working one day, The one in there now is a used unit from some chop shop in Texas. The only reason I kept Dell #2 around so long is that it has a development environment on Windows 2000 that I needed to use for some contracting work. Always hoping Id get a call to do more work, I kept the machine around and running cheap.

Dell #1 is also a win2k, that runs and old version of Reason, and a REALLY old version of Sonar.

Not averse to getting a new computer, but this one is basically a 'net computer, so I don't need much from it. Will check all the voltages first, then see if a fan will work from one of the other old Dell's.

Would rather put $1,000.00 into another guitar amp, than buy another PC!

[bob p]

I have to sheepishly admit that I had a 486 box running as a router, and the only reason that I had to replace it was because one of the ISA 10-base-T networking cards failed and I couldn't find another one. So I had to rebuild my router using a Dell P3/800. I've still got a P2 machine that runs as a SMB server. I built it by compiling Linux from scratch back in the 90s. It's still working without any component failures. Compare those old boxes that will never die to some of the newer boxes that are designed to die right out of warranty, hard disks being the worst offenders.

[Steve A.]

I have a 11 year old Dell E510 computer. Was OK for what I need (post on the blogs etc).

A few years back, the CPU fan started going wild under load. I took it apart, pulled the CPU heat sink of, cleaned it off and put some new heat sink grease and it was better for a while (year or so?)

Recently, maybe a year, when its under load, the CPU fan goes to max, and the computer slows to a crawl. Since its WinXP, I can't find any software that will read the actual CPU temps.

I pulled it apart again, really cleaned the cpu case and heat sink, put new heat sink grease on again thinking I screwed up the last time, and this time no improvement.

Its like running on half a CPU. Tried a different hard drive I had setup with Win7 (clean drive), thinking maybe a virus or some other crap software was causing the problem, same thing.

The fan noise is awful, but the CPU spikes and everything slows to a crawl.

Anyone run into this?

Thanks!!

I've had problems like this when the fins in the CPU fan get clogged up with dust. I think that the CPU senses that it is getting too hot so it speeds up the fan.

Are you sure that the CPU cooler is clean and making good contact with the CPU? I've had the mounting brackets break...

Good luck!

Steve A.

P.S. You can get seller refurbished off-lease computers dirt cheap on eBay ($50) or spend a little more for the ones that are factory refurbished ($100.)

[Steve A.]

Have you tried just replacing the little fan?

There are many different types of CPU coolers so you need to find one that will fit your CPU and motherboard. Getting one from the vender (Dell) can be very pricey assuming that they are even available.
A local computer repair shop might know what to order.

Besides the fan seems to be working great running at a crazy fast speed but the CPU is still overheating - or thinks it is.

[mikepukmel]

Thanks Steve, I have taken the whole thing apart, blown/vacuumed out, washed the heat sink fins out, didn't seem to help. Oh yea, replacement parts from dell are ridiculous.

That's what bothers me: I can't tell if the CPU is actually overheating, or if there's a problem with whatever thermocouple is in there. Is there a thermocouple inside the CPU? After running fro a few hours, if I put my fingers on the heat sink, as close to the CPU as possible, it is warm. Not so hot that I can't keep my fingers there.


V1: 5.12V fairly steady. (bounces to 5.13 ... 5.11, not outside that range)

Jeff Beck, Stevie Ray Vaghan, and Bireli Lagrene videos playing simultaneously, and winzip going as well.
Needle pegged.
Fan motor is up but no quite max.
5v rail holding 5.12v steady (+/- 0.5)
12v rail 11.86 steady (was about that before.

Noticing that with the computer cover off, fan is not going quite as high.

Added two more youtube videos, and a dvd ... voltages holding.

Will pull the heat sink off and see how badly I screwed up the heat grease.

[mikepukmel]

I have to sheepishly admit that I had a 486 box running as a router, and the only reason that I had to replace it was because one of the ISA 10-base-T networking cards failed and I couldn't find another one. So I had to rebuild my router using a Dell P3/800. I've still got a P2 machine that runs as a SMB server. I built it by compiling Linux from scratch back in the 90s. It's still working without any component failures. Compare those old boxes that will never die to some of the newer boxes that are designed to die right out of warranty, hard disks being the worst offenders.

Oh man, hit a nerve there. I saved (to my wife's displeasure) my 486DX2 66 Compaq I bought around 1990. It was the first PC I bought, for software development. Still boots and runs fine. And I just tossed due to lack of space, two big steel tower no name computers, from the early 90's as well. I would have kept one of them, but could not get Linux device drivers for it.

Stuff you get now is an insult.

A few months ago, I bought a new Dell 3610 for software development work, the web page made it look like a solid workstation development machine. When I pulled it out of the box, the case flexed, the sheet metal was so thin. I plugged it in and you could hear hard drive and fan noises all over the place. I packed it up and sent it back. And it wasn't a cheapie. Not the top of the line workstation but not a 499.99 either.

[Enzo]

Steve, I mentioned replacing the fan, because here without the thing in front of me, it sounded like he might have a fan wearing down its bushings, causing it to be overly noisy when cranking, and cranking because it was no longer spinning at full volume and moving sufficient air.