Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Motherboard won't start-Mobo or CPU?

Status
Not open for further replies.

mingyar

Programmer
Nov 3, 2001
25
US
I just got an ASUS A7V8X-X with an Athlon XP 2400. When I turn on the power supply the Mobo power light will come on. However, when I try to boot the machine the CPU fan will come on like it's trying to start but then it stops and won't do anything else. I already check the memory installation, power supply and Drives. The heat sink is properly intalled but I did not used any thermal grease when installing the CPU.
Does anyone has any idea of what could be causing this?

Any help or suggestions will be greatly appreciated.
Mingyar
 
hello mingyar,
Re-check the data and power cables for the drives. Make sure all cables are connected and are not backwards. Inspect all add on cards to insure that they are fully seated in the slots. Particularly the video card. Or if that doesn't help, disconnect everything leaving just the basics (cpu,memory,video). Also make sure the keyboard and mouse are not connected backwards.
 
Some things to check for:
1-CPU COOLER is installed properly. Must be level make sure the cutout part is facing the right way which toward the top of the ZIF or CPU socket.
2-CPU Cooler fan is plugged in to the CPU fan power on the motherboard.
3-Make sure the motherboard is not grounding out to the case. Sometimes the risers you are suppose to mount the motherboard to are in the wrong place. The motherboard can not touch any other metal parts except where the mounting holes are, and they must line up properly. This is a very common mistake. I have even seen people screw the motherboard directly to the plate with no standoffs or mounts. This would be a bad thing.
4- When nothing works remove all drives and all PCI Cards and try to turn it on with just a video card and one drive like a floppy of a CDROM. Cards can ground out if not inserted just right. This leaves the fewest possible number of things to go wrong. You may have to set a jumper or two on the motherboard. Your CPU XP2400+ is a 266Mhz (133Mhz X 2) BUS SPEED CPU. If the BUS speed is wrong it may not autoselect properly. Using autoselect is a good idea. You may be able to use a autoselect jumper for jumper free mode. This lets the BIOS choose the setting. Often this works fine. Other times you have to flash the BIOS. If you have PC3200 (DDR400) RAM try a different stick of RAM like some old PC2100 (DDR266) RAM to see if it will boot. Many times it is incompatible RAM that causes problems. The RAM may be good but not for your motherboard.


If you do not like my post feel free to point out your opinion or my errors.
 
I added thermal grease to the CPU and it now stays on. It sounds like the hard drive is running, the CPU fan is running and all the mobo lights are on. However, nothing is comming up on my monitor at all. I already removed all PCI cards and drives except for the HDD. The mobo manual says it's a jumper free mobo. Does anyone knows what my problem could be?

Any help will be greatly appreciated.
Mingyar
 
Try disconnecting the hard drive. The cable on it may be backwards as well.
 
I checked the cables on the hard drive and it's connected correctly. Could it be the CPU??

Any advise will be greatly appreciated.
Mingyar
 
mingyar you "added thermal grease to the CPU and now it stays on" unfortunately you don't get any second chances with AMD XP CPU's, if the heatsink was fitted without thermal grease it would have only taken a 20seconds or so to damage the CPU permenantly, and I don't think this motherboard has on die thermal protection (latest Nforce2 and KT600 motherboards do)
Martin

Replying helps further our knowledge, without comment leaves us wondering.
 
I have been having a similar problem. When I turn on the machine, the CPU fan and System Fan start and then they just stop. I have tried several configurations including taking the cards out and unhooking the drives. I have even flashed the bios. I know there is power to the board, as the atx power connection has an LED on it. The funny thing is the machine has been up and running for over 2 months now and all of a sudden it starts this. Any ideas would be appreciated.
 
If the CPU is burnt-out jou should be able to smell a sharp burnt smell on the CPU and the little blue chip in the center of the CPU will be discoloured. Some times you will see dark/black marks on the CPU.

A lot of newbies leave the wax paper on the bottom of the cooler that keeps the Thermal pad clean and fresh. This will insolate the CPU enough to cause it to overheat and burn. Take the CPU back to the shop you got it from and ask them to test it for you. If the CPU works fine at the shop try the following:

Some times with new Mobo's it won't POST at first until you reset/clear the BIOS.

>>First make sure you unplug the power to the power supply<< give it around 15 seconds then you move the jumper to clear, give it 15 seconds then you move it the jumper back hold.

If you don't have a the CMOS clear jumper you can also pop out the CMOS battery and short the the two contact inside the battery holder. ALWAYS make shure that you do not have power to the power supply when you do this.
 
Paparazi,
I think the CPU works fine. We tried to start the mobo with another socket A CPU and it did the same thing, plus the mobo has a feature where it would shut down if it felt any overheating on the CPU (it would not stay on for more than 3 seconds before the thermal grease was on). Unfortunately, I think the mobo damaged the HDD and CD/RW drive because now none of those two will work.

Thanks for your help.
Mingyar

 
Are You 100% That Its Not A PSU Problem because to it sounds like the psu itn't keeping the Power on therefor the CPU Fan,Etc would only work for a few seconds.

Have You Tryed a Another (Working) Motherboard in the pc and see if that works

________________________________________
I help Where I can, If My advice Dont work Or Is Wrong then tell Me

brussandpony.jpg
 
Yes, I actually tried it with another brand new psu which is working perfectly on another machine. As I mentioned on a previous post, the CPU fan started satying on after applying thermal grease to CPU. However, nothing would show up on monitor and no beeps would come out of mobo. After some troubleshooting the CPU wouldn't even turn on anymore.

Thanks for your help.
Mingyar
 
I might be asking a stupid question mingyar but did you plug the extra 12volt 4 pin lead into the 4 pin socket that is located not to far from the USB ports?
 
Sorriez was looking at the wrong picture just forget about my last post...
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top