fan runs full speed at start up

[mpw101]

I have a scratch on mine that is my own fault.  I may get some of that stuff.  It's just a surface abrasion.  Well only time will tell if the factory repaired your computer.  I guess it is quiet at the moment.  Hope the quiet starts continue.

[scotsilv]

It works like a charm on the shiny plastic surfaces  Perfect results.  I applie it with a very soft microfiber applicator.

[scotsilv]

Well, it didn't take long.  I've shut off and powered up the machine over the past two days about 10 times.  In just powering it up now, the fans went into fullspeed mode (4000= RPM and 2000+ RPM).

This is a new motherboard, and BIOS 7.17 (the motherboard that was replaced had BIOS 7.19).

The intermittent high speed fan problem at powerup corrects itself by ctrl-alt-del or powerdown-powerup cycle via the power button.

My opinion is that this is a BIOS problem, but nobody at HP seems to listen.

I am just going to live with the problem; if racing fans ever stop responding to reset, I will simply throw the motherboard away and build a new machine using the existing parts, with another manufacturer's motherboard, and deal with Microsoft regarding the Windoes 7 license.

[mpw101]

Sorry, but I guess we both knew it was going to happen.  I do not have the ability to build my own.  At times a couple of the case managers, I think, doubted me when I told them what was happening.  Fortunately HP made good and gave me another or I don't know what I would have done. 

I just didn't think letting it continue was a good idea.  Seems like it would have happened to more people than just you and me.

Well good luck. 

[scotsilv]

I can't imagine we were the only two, Carmel2 is a common motherboard in many HP machines. Maybe others don't care and just reset their machines when this happens?

I for one do not like mysteries, but there seems little to be done.

[scotsilv]

Well, after a few months the problem is at least stable.  Fans will go to full speed appx. one in gten powerups, throttle down to normal after immediate ctrl-alt-del (even before booting).  And this is the replacement MB installed by HP.

I am beginning to think it's a BIOS problem, e..g, timing of some hardware initialization, with this MB and the Pentium G630 in the P7-1222.  Else every machine using the Carmel 2 motherboard (lots of them, mostly with faster CPU's) would exhibit this behavior.

[scotsilv]

The mystery *may* finally be solved.

Before my warranty ran out, I spoke to HP's (U.S.) service center and explained the problem.  The tech suspected a defective CPU since a motherboard replacement mande no difference.  I got a new service order # and a shipping box.

Received the unit back from HP.  Again, only the motherboard was replaced according to the work order.

However after a week's use the machine no longer seems to go into intermittent full speen fan mode on powerup.

I believe a number of boards have defective LPCIO's that don't initialize properly sometimes, resulting in temp readings of 99C and causing the fan speed algorithm to put fans at max. 

The new (third) motherboard is the same Carmel2 but on the tiny labels I note revision 2.00.  I do not know the revision number of the original and second motherboards.

Keeping my finger crossed the problem is solved, and leaving this for any others who might experience this annoying problem.

[scotsilv]

Spoke too soon.

Problem recurred again this AM - fans running full speed at powerup.

Back tp HP.

[mpw101]

I did not think a week was enough. My original computer at times went even longer.  I have not had a moments problem with the replacement computer HP sent me when repeated efforts to stop the fan racing did not work.  But as we discussed months ago, I have a different motherboard in the replacement computer.

I can now add that with the original computer the HP splash screen appeared for a few seconds.  The fan would already be roaring even before it came on the screen. 

In the replacement computer, when I start it, the HP flash screen appears for a nano second; does not even fill the screen.  It literally flashes.  I would have no idea what it was if I had not seen it on the first computer.

I have no idea if this is relevant but thought I would mention it.

[scotsilv]

Ok.  Think I solved the mystery.

As earlier in this thread, I posted a screenshot of SIW sensor readings when the machine had fans fullblast.  TMPIN1 was reading 99C, an impossible value, athough CPU temps were OK.  I did not know what TMPIN1 was.

Ran a CPU stress test, Prime95, and lo and behold - CPU temps shot up as expected to the 51-52C range....AND SO DID TMPIN1.  Therefore TMPIN1 is CPU-related.

Therefore I suspect - and as did the prior HP tech I spoke with before repair attempt #2 - the CPU is probably flaky, not initializing properly on powerup. 

Unfortunately someone else at HP then swapped the motherboard for the second time instead of replacing the CPU.

So I gave up on HP and just bought a brand new Intel Pentium G630 CPU and put that in the machine.  I used the old HP fan, with new thermal grease of course.   It took about 5 minutes.   (I've built machines from 486's and up.)

Let's see if that now stops the problem.  Considering it's a new motherboard and a new Intel-boxed CPU, there's nothing else electronic that could be the cause, and I really, really doubt a defective fan or hard drive would cause the TMPIN1 CPU-related reading to be 99C at startup.

A CPU fault may also explain intermittent Windows boot failures "cannot connect with XXXX services" as well, images of the errors which I posted in this thread somewhere.

The new CPU cost me about $65 but at least now I think I have a computer I can trust.

And I think Intel has a lifetime CPU warranty.  Have to check - I may be able to get a fresh Pentium G630 replacement for the defective one, now sitting in the package from the new CPU I bought.  At least then I'll have a spare  🙂