CPU fan problem. Help!

[kdeank]

I just booted up my computer for the first time (homemade EPOX KHA+
mobo, Athlon XP 1800+, INWIN case, Mr. Cooler 300w power supply, Dr.
Thermal TI-V77 CPU heatsink/fan by Thermal Integration Technologies. All
OK except the CPU fan did not come on. I re-checked the connection at
the motherboard to no avail. BIOS confirmed 0 rpm on CPU fan. Next, I
connected the CPU fan to the motherboard connector for the case fan (fan
2), and connected the case fan to the CPU fan connector. This time, both
fans worked on power-up, but the BIOS knew something was amiss.

So, the CPU fan functions, but not when connected to the CPU fan mobo
connector. Likewise the CPU fan mobo connector functions, powering the
case fan and reporting fan RPM, etc. They just don't work when they are
connected correctly.

Oh, and I can't get though to the web sites of either mobo or CPU fan
manufacturer.

Any ideas?

[fred]

Hi kdeank,
I am perhaps not the best person to comment on this, because I don't know the
EPOX KHA+ fan hardware/software, but I did have a similar situation with another motherboard. It powered up with a dead CPU fan. It turned out tha it was a faulty board and there was no current coming out of the socket! All I did was, like you, ran it from a different fan output on the motherboard and disabled the CPU fan alarm in the BIOS.
I would say you probably have to do this or return the motherboard for another - a shame if everything else seems fine! But wait a bit longer to see if someone here knows of something specific for your MB and see what your shop says first..

[morriswindgate]

I am not familiar with your heatsink unit, but I do know that the size of the fans and the power they need to run properly has reached a point to where they shouldn't be connected to the motherboard. I am not familiar with that model EPOX, but I would run the fan off of the power supply directly, and then disable or remove the software the is monitoring the fan, and if it fails toward the end of the warranty or if your leery now gat an RMA (Return Authorization)from EPOX. Their tech people are really good at answering e-mails.

[kdeank]

Now I've studied the Dr. Thermal CPU cooler box a bit more, and perhaps I've found the problem. I have an Athlon XP 1800 CPU. The box says:

"[/I]Designed for overclocking PIII 1.13 GHz+ /
AMD Athlon 1.4 GHz+ /Athlon XP 1900+[/I]"

Could a fan that was compatible with these not be compatible with an XP 1800?

BTW, the manufacturer web site is still down, and I have not received an e-mail response from them.

Also, I note that this cooler is not AMD-approved. Newbie mistake. I was looking for a cooler that would not sound like a hair dryer. This one is definitely quiet, as advertised (when I hook it to the case fan jack).

I will take your advice on hooking the other fans directly to the main power supply, but the BIOS does not like it when I don't have anything hooked up the CPU fan jack - it seems to get some important info through hat. Any advice?

Thanks for your help.

[FONT=century gothic]

[crjdriver]

I am not familiar with the EPOX board. It probably has some type of alarm in regard to fan rpm from the fan 1 connection on the board. You should be able to disable this from the bios. Make absolutely sure that you do not power up the CPU without a working fan. It can be damaged in just a few seconds.
If you have a voltmeter you can check for voltage at the fan 1 connection. If there is no voltage you probably have a bad board and you should return it. You might try powering up the board outside the case [if you have an extra power supply handy] this will tell you if something is shorting out the fan connection when the board is installed.

[Cricket]

Hi kdeank,

That particular heatsink should work fine with your Athlon XP 1800+...seems it will handle up to a XP1900+.

After reading your posts, it seems as if you'll have to connect the case fan to the CPU fan header and connect the CPU fan to the case fan header. This arrangement does allow the fans to work properly and allow your system to boot up. This won't hurt anything as you just need to get the fans working. Just remember which is which when you check the BIOS. Seems this is one of those motherboards that must have a fan connected to the CPU fan header in order for the motherboard to power up...it's a sort of protection to make sure the CPU has some kind of thermal cooling so it doesn't burn out.

Try you system as above and see if it will POST (Power On Self Test). If it doesn't, try taking the parts out of the case...see this link: http://forum.pcmech.com/showthread.p...threadid=12753

If you still can't get the system to start up, there's a chance the CPU got damaged when the CPU fan wasn't working.

Cricket

[kdeank]

Thanks for the help. I did try out a new cooling fan and it made no difference. Seems like I just have a bad CPU fan header. I went out and got some of the 3-4 pin power adapters, and have been able to run OK with the CPU fan hooked up to the main power supply. I don't know if it's worth the trouble of returning the motherboard for this.