Monitor will not work after installing new CPU fan

I am trying to repair an old HP Pavilion 754v PC. Recently it displayed a message on my screen stating CPU Fan Failed Shutdown Immediately! I did in the case of frying my proccesor which is Pentium 4. So I opened up my tower and pulled out the CPU Fan mounting on my motherboard (Processor looks in good conditon, with the exception of the white or should I say gray residue that each CPU fan leaves after installing). I looked at the socket number which is 478B and bought a new CPU fan for it as well as a 92mm fan which needed to be replaced very badly. After installation was completed I turned on my machine without putting the case cover on (in case fans wouldn't run) turned on my computer (fans ran fine) and my monitor wouldn't display anything, but the tower was running fine. Is it possible that the CPU fan is putting out too much power that my macine can't handle it or could it be something else? Also, I used this machine the day before when I had the old fan in and the monitor worked fine. I should also state the new CPU fan that connects to the motherboard requires a three pin connection in order for the fan on top to work; however, I used an extension with three pins and a black ATX power connection to plug into the motherboard and then plugged the black ATX power connection into my P5 power connection (that's how I got the fans to work). Help Please!

 

You should make sure the cpu is supported by the pc/mobo/bios before buying. Either hp.com or the user/ref. manual lists this info.

So you're saying the pc turns on, lights & fans come on, but the screen is blank? Power off, clear cmos, look at your manual for how. Typically, you unplug power cord, take the battery out & short 2 nearby pins labelled CLR for 1 min.

Clearing cmos may not if the mobo is fried.

 

What?

The mobo should have a standard four pin fan header/conector. Even if your fan has only has a 3 pin connector you should still be able to plug the fan directly in to the motherboard. The header/connector should have raised plastic guides to ensure that you plug the fan connector in correctly. Plug the fan DIRECTLY in to the motherboard's fan header/connector.

Boot the computer if the fan doesn't spin up your header has blown and the motherboard is dead. Please note that the computer will still power up. Everything else will power up, any other cooling fans will spin up and your graphics card will even power up but the computer won't even get to the POST screen (ergo no monitor activity.) I know this because I found out this the hard way when I shorted my CPU fan header and blew the board.

Since you've been inside the computer did you notice any odd or strong smells (burnt circuit board has a very distinctive smell.) Did you also check around the board to see if their were any noticeable burn marks or components that looked damaged?

I assume you checked the old CPU fan to find out that it was fan that had died and not something else?

 

Some 'puters have a safety feature where if the CPU fan that is plugged into the mobo dies, the computer will not boot. If you are running the CPU fan off an adapter, you need to go into the BIOS and set it to ignore the CPU fan.

Also, the white stuff is TIM (Thermal Interface Material) or some other acronym that is lost to me right now. But it is important to have. I like Arctic Silver 5. This stuff is a paste that helps heat transfer from the chip and the heatsink. You need to put some of that on. If you need help on how to clean the CPU and apply the paste, let us know.

Do you get any beeps when you start the computer? Can you get into the BIOS? To get in the BIOS, you normally boot the machine and hit the Delete key, F2 or another button to enter it. Does anything come up on the screen when you start the 'puter?

E

 

No nothing comes up on the monitor. also I probably didn't explain myself very clearly in my last message I see some are thinking that the fans aren't working, but they are and the motherboard is not fried because if it was then the fans wouldn't work. I think what the problem is is just that the fans are using a lot of AC usage, so much that my system can't handle it. Remember it is an old computer. Another, reason I believe this to be true is that whenever I disconnect my power cable from the back of my tower for about 10 seconds then plug it back in, the fan, not the one on the motherboard, but the one on the back of the computer with the blue LED light flicks on then off real quick, kinda like when you come into a room and turn on your lights and all of the sudden your light kicks on then off because a bulb has died. It's kinda like that. However, I do appreciate the tips and I'm sorry for not explaining myself clearly, but if you can think of anything else let me know. Thank you.

 

I suppose it could be a PSU issue but for it to be unstable enough that running a couple of fans off it is causing the GPU to not get enough power... it would have been pretty flaky prior to the failure if the PSU 12V rail was being affected by a few fans.

Strange, what kind of power supply is it running and what kind of GPU is it running?

 

AC Input - (47-63HZ) 100-127V-16A ; 200-240V-13A

DC Output - +5V=/23A , +12/V=/10A
+3.3V=/10A , -12V=10.8A
+5VSB=/2A

+5V & +3.3V Shall not exceed 148 W
+5V & +12V Shall not exceed 163 W

Max output power = 200W

Rated power for the Spire 414S8-H is 3.6 W

This is the my power supply information for Model HP-A2027F3. I might be reading this information wrong, but if the rated power for this fan is only 3.6 W and my machine is capable of handling 200W then it can't be a Power Supply issue, is this correct? As for my GPU I'm not really sure.

 

I'm still pretty baffled by your explaination of how you hooked up the CPU fan with all those extentions. The cpu is cooled by a combination of a heatsink and fan. Typically when you buy a new one you will get both a new sink and a new fan and the fan will have a 3 pin connector of the type that plugs directly to the motherboard into the header just for that purpose, and if its not right the pc will not start. If the PC is not seeing your cpu fan then it thinks there is none even if its running and will not start.

Again, the cpu fan must be plugged into the motherboards CPU FAN socket or the PC will not start. If the fan you bought to replace the one that stopped is not a true cpu fan for the heatsink with a three pin plug you have the wrong fan.

All that still doesn't make sense from your description because you stated that you bought one for a socket 478, and that would mean you bought a sink/fan combonation, and there is no way if you did you would have to use extentions to get the fan to run, it would plug directly to the motherboard very close to where the sink mounts.

By the way, that grey stuff is thermal compound and should be cleaned off and replaced before you run the system. Most people use Artic Silver thermal compound.