I've tried pretty much everything here, I'm just about ready to go buy a new mobo. I bought a passive cooling heatsink for my A8N-E mobo's northbridge chip (nforce4, runs fairly hot but zalman guarantees their chipset cooler will work in any non OC'd situation) as I found the stock fan was making far too much noise. I went through the standard procedures for performing this task, something I've done numerous times before. I did find however that I needed to remove some sort of adhesive thermal tape surrounding the chip in order to ensure a clearn work surface (thermal paste remover had slid in behind it). anyways...after installing my new NB heatsink I proceeded to boot up my computer. The computer booted up fine originally. I started by going into the bios to disable the NB low fan speed warning. No problems yet. After saving my bios settings I rebooted my computer. As my computer rebooted it suddenly dropped it's video signal and proceeded to beep (pheonix bios beep 2-1-1-1 which evidently serves no real use in trying to identify your problem). I felt the heatsink on the NB to see if it was hot or not. It was incredibly hot which re-assured me that my installation was performed correctly as you would expect heat to be transfered to the heatsink. I went on to double check every single component in the system, everything seemed to check out. My next step was to re-install the originally supplied HSF, which turns out didn't correct my issue. Over the course of my several reboots during various stages of my troubleshooting I always found that if I let the system off for a long enough preriod of time I would obtain a video signal (and no beeps) but only for a short time, then the video signal would kick out again. This would then lead me to have to reboot, which you guessed, would result in a dropped video signal and the 2-1-1-1 beeps. All of this leads me to believe that 1 of 3 things has occured. (1) that I somehow incorreclty installed the HS/HSF twice and that the NB is shutting down the system as a safetey measure (reinstalling a 3rd time may do the trick). (2) I incorrectly installed the first HS and permanently damaged the NB chip causing my computer to behave eradically (need to buy a new mobo if this is the case :<). (3) I installed the HS correctly but this particular Zalman product sucks and destroyed my NB chip despite assuring me that it would not do so (still need to buy a new mobo but will swear off all zalman products). Thoughts? I've just spent the past 6 hours trying to remedy this situation through hands-on troubleshooting and extensive internet searches. Quite frankly I'm exhausted and any feedback to this email would be very much appreciated. Thanks in advance for any advice you can provide.

did you put thermal paste on the chip to allow a contact between the chip and the heatsink and i dont think it would over heat im quessing it is beeps warning you of overheating Hope it helps a little GOOD LUCK :) Damian Pentium4 3.20ghz@ 3.5ghz 1Gb Crucial XMS PC3200CL2 1 X 80GB HDD OS 1X 40GB HDD STORAGE NVDIA GeForce4 MX4000 Pro ASUS P4-U800-X 600w PSU 12v 1-14amp 2-15amp WinXp

yup, sure did. I even placed a fair amount of thermal paste around the chip where the makeshift thermal tape was prior to my installing the new heatsink. Do you think the mobo is still good? Have you ever heard of a partially fried chip that could exhibit this kind of behavior?

The chipset cooling fan problem is very common for that particular board...you should have discovered that fact when you were researching. Asus would have supplied a free replacement, had you contacted them. "I even placed a fair amount of thermal paste around the chip" What does that mean? You should have used a very small amount of paste, about the size of a BB, then spread it thinly & evenly over the top of the chip. And all traces of the previous thermal compound/tape should have been removed from the chip & the chip thoroughly cleaned prior to applying the fresh paste. It's usually recommended to rub a small amount of paste onto the bottom of the heatsink, then wipe it off with a lint-free cloth. This helps to fill any microscopic gaps.

I would reset cmos to default settings and see what happens (above it looks like the problems started when you turned off the low fan warning), take the case cover off and blow a house fan into the open case to keep it cooler, try switching out the psu or at least checking to see if its fan is still working, check every fan to make sure they are spinning, try running at minimum cpu/memory/fsb speeds (maybe there are mobo jumpers that allow this if you can't get into bios to change it), try a new vid card, try reinstalling the NB sink. Heatsinks other than cpu heatsinks often have lame plastic connection methods that wear out quickly. It does sound like a heating problem btw so don't give up yet.

to the 3rd response: The nforce4 chipset is a little different then your standard northbridge chipset. In this case the top side of this chip is very small and only encompasses about 25% of the surface of the actual chip. I believe that's why the thermal tape surrounding the chip was there to beging with. This leads me to believe that I need thermal tape to place around the chip as asus had done with the original factory installed HSF. I'm beginning to believe that in order to properly cool the chip I'll require replacement tape. Also as an added note, it's not that I require a replacement HSF, I still have the original and it works fine, but what I was trying to do is switch over to a passive (non-fan) solution to help elliviate the noise. To the 4th response, I have tested every component in the system, i'm sure the culprit is the northbridge, but what I'm wondering is if the chip can be permanently damaged by insufficient cooling. My goal today is to locate some thermal tape and perform the installation with the original HSF combo and see if I can get some stable operation (or stable boot up). Thanks all for the responses thus far.

According the this page: http://bioscentral.com/beepcodes/phoenixbeep.htm A beep sequence of 2-1-1-1 = Set initial CPU speed Do yourself a favor BACKUP!