Each time I boot up, or even press the reset button, the heat sink will get power and spin for about 10 sec. After the initial power from either turning the comp on or reseting, the heat sink fan just winds to a halt. Of course, if I keep the computer on long enough, it will just shut off, but ever since I noticed the problem, I never leave the comp on for more than about 15 sec. if the fan is off.
This was not the original problem, but in solving the first issue, I seem to have created another. Any ideas? In order to solve my first problem (wouldn't boot up at all) I disassembled everything, then re-connected all the wires after taking out the MoBo battery for 10 sec and reseting the bios w/ the jumper pin. I don't think I bumped the heat sink or fan at any point, and the fan is obviously getting some power, but it then stops very soon after.
Hi Kaspar welcome aboard.
First of all make sure you have caught no links or DIL switches on the mobo that sets the clocking speed, more important ensure that the fan CPU fan is not sticky... it should be free to spin when flick by a finger or pencil, the machine will shut down should the CPU fan fail, you can check the fan quite easily by removing the connector and applying 12V dc, from a wall wart or a 12V battery... +ve to red wire and -ve to black wire, usually the two outer ones, some fans may have a third wire for monitoring the fans speed and is usually the middle one on the connector.
NOTE: The fans should spin as soon as you switch on and is powered from the 12V from the power unit. I would try removing the graphic card and re-inserting it just to be sure it's seated properly.
Well er, what next?... think it's best if we get down to basics, we need to disconnect all thats not required and concentrate on getting the bios to boot or properly known as POST, Power On Self Test when you first power up - this must be your first goal as nothing will happen without it.
Disconnect all drives including the hard drive and all USB devices all we need is the Graphic card and RAM installed.... "yes yes, we need the Mobo, CPU and power supply installed as well" . With just this 'bare bones' set up you should be able to get bios boot and if required be able to get into bios set up. If all was well here you would get a message similar to 'Disc Failure', 'No Hard Drive Found' or a much kindlier message 'Please Insert the The Operating System Disc' simply because we disconnected the hard drive, it wouldn't just sit there winking at you.
So this leaves the installed components to cast evil eyes at if it's still not working, see how we go from here.
Thanks for the help so far, currently, I can actually get the computer boot up, I've entered the BIOS, and can stay on for about 10 mins or so before the computer shuts down automatically. I monitored the startup temp. from the BIOS, and it usually starts around 55 deg. F, then rises slowly, and the comp shuts itself off when it gets to about 70 or 75 deg. F. I haven't let it get to that temp very often. I can let it boot to Windows if I want, but it usually gets to that 70 deg. during loading time and shuts down. In the BIOS I tried adjusting some of the fan speed settings, but I don't know my way around BIOS all that well. I think I turned something on called Smart Temp or something like that (Didn't fix or even influence the problem.)
Question about testing the fan, you said I can do it from a wall socket, would I just take an old lamp / extension cord and the ends to connect to the 3 pin housing I normally plug into the MoBo? Of course I'd do all the connecting first, then plug it in after I've got it stable w/ elec. tape or something so the wires aren't touching me or each other. Is there a better way to test the fan itself? (I can certainly find an extension cord that I can cut into if needed.)
Anything specific I can check for in the BIOS since it's able to get up and running, accept changes, and save & exit? Last, where on the MoBo might the links or DIL switches you were talking about be? I can google them to see what they look like, but I'm unfamiliar w/ those. Thanks again!
Sounds like a overheating problem as you hinted, some CPUs will cut out when they overheat to prevent damage... and yet some don't. I would try and look at the specs for that CPU, the temperature seems a little high to me, the heat sink fins not full of dust will cause overheating, what about the fans RPM does that appear to be normal?
I would first check the CPU clock speed settings in the bios menu, just in case some switch or link has been disturbed. The link or switches to set these depends on the mobo, some as miniature slide switches, some uses links and some does it automatically, checking in bios will tell you if they are right or not.
Testing the fan.... you can use one of those little DC adapters that you plug into the wall, some folks call them a wall wart they a little power supply unit, Don't plug the fan into the power or light socket directly - you need a 12V power adapter the kind of thing you get with portable radios and tape recorders so that you can run them of the mains power to save using the batteries.... if in doubt use a 12V battery.
Quote:
you can check the fan quite easily by removing the connector and applying 12V dc, from a wall wart or a 12V battery... +ve to red wire and -ve to black wire
The fans are operated from a 12 Volt DC supply, if the red and black wires or polarity is wrong the fan will not work.
So, this is somewhat embarrassing, but it turns out I had the fan plugged into the wrong socket on the MoBo. I put mine in the Northbridge Cooling fan connector instead of the actual processor fan connector. I'm sure it was getting somewhere between 2 and 10 volts, but not the 12 it needed to maintain its spin. Thanks for all the fast replies and ideas though!
Heat sink fan starts, then stops 
Linear Mode
