A7V800 wont start with AMD XP2500+

Hi,

I just bought 3 identical systems (for my father, brother and me). They all
look like this:
- ATX midi-tower with 350 W powersupply
- ASUS A7V600 mobo
- AMD Athlon XP2500+ cpu
- 512 MB DDR400
- ASUS V9520 videocard
- HD, DVD, and floppy-drive

When I had build up the first system and pushed the power-button, it came to
live and immediately shut down within 2 seconds. No beeps, no screen.
Checked everything around, nothing found.
So I build up the other 2 systems. Guess what? All 3 systems have the same
problem!
Checked all jumpers again: all on "default". And no junpers that do somthing
with CPU-settings.
Then I started troubleshooting by detaching as much components as possible.
The system-power only stayed on, when the CPU was removed. Conclusion: the
combination mobo/CPU doesn't work. But AMD recommends the A7V600 for this
CPU. So what did I do wrong? This is my first computer that I build up.

Then I replaced one of the CPU's with an old AMD Athlon 800. Then the system
started normal!
Any suggestions how I get the Athlon XP 2500+ to work on this mobo? I don't
belief in 3 defective CPU's;-)

Thanx for your help.

René

 

Sorry: Subject must be "A7V600 wont start...."

 

What kinda heatsink you using......?

 

I bought the cpu as "box", so it's that standard big heatsink+cooler.
But believe me: the cpu doesn't even get the chance to get warm!

 

I've built a number of systems with Athlon XP 2400, 2500, 2800, etc.
They are super sensitive to the attachment of the heat sink. Twice I
had the same trouble you described. In each case, I removed the heat
sink and found that the thermal patch had not made very good contact
with the processor. I thoroughly removed the patch and its remnants
from the processor and the heat sink, and applied a coat of white
thermal grease. After putting the whole thing back together, both of
them ran like a champ.

Something about pushing the heat sink onto the processor does NOT
guarantee that the thermal patch material will spread out and cover like
it should. Whenever I build a system now, I remove the factory applied
thermal patch from the heat sink and assemble the whole thing with
thermal grease.

Hope this helps.

 

hummmmmmmmm

 

oh, as long as theyre attached. I had the same experience when I built my
rig a while ago without a heatsink -heatcop kicks in immediately (just as
well) You can run with fan off -for a while.

 

Make sure the cpu fan is connected to the proper plug on the mobo. If the
fan rpm is not detected the computer will shut down after 2 seconds.

 

I just gave it a try with the cooler from the Athlon800: same result,
shutdown within 2 seconds.
It looks like C.O.P. is overreacting! But why does the Athlon800 run
smoothly, while the XP2500 gives this bad result?
What makes the XP act different from the Athlon800?
And can I do something about the C.O.P. on the mobo? There's nothing to find
about that in the manual.

René

 

Im a bit stumped then René. Using the athlon 800 can you try manual
settings in the bios and then, power off, switch cpu, power on..
Try getting the xp2500 started using 333fsb or 266fsb and the 400 memory at
333, and vcore at 1.65, multiplier at 10. This is slightly slower than it
should go but it could be a start. Id be hopeful of getting it to run at
400fsb/mem x10 multiplier for xp2900~ performance -eventualy.

Asus's manual bios options provide a lot of freedom to run at different
speeds -once you get going.

Bios is up to 1006 so it might be worth a flash too,
http://www.asus.com/support/download/item.aspx?ModelName=A7V600

gl,
pief

 

Try clearing your cmos first and do it properly. Commonsense dictates that
if it works at 66 MHz FSB then it is going to have a problem with 333 MHz
FSB chippies.

 

Already cleared the CMOS. Problem stays the same.
I don't get your common sense.... My problem?

René

 

Thanks voor your suggestions. I will try this with the Athlon 800 later
(don't have much time these days).
But I don't like the idea that I need an older CPU to get the new one
running. And when I flash the BIOS I can start all over again?

René

 

I threw an A7V600 together with an XP2500 CPU and DDR400 Kingston ram and a
GeForce5200 AGP card and used the on board sound.
On first boot I enter Bios setup and set the time etc etc and move on to FSB
speed etc. The 2500 is set at 166 FSB (166x2=333) and a multiplier of x11
and so on till I save and Exit.
The next boot is a full boot and I lay a copy of XP Pro.on the HDD.
I do not attempt anything more than standard settings at this point because
I need to know if I have just built a good, working computer. I will fiddle
with the settings later when I am happy with my new computer.
I think your older CPU has a FSB of 100MHz and it just seems to me that if
it boots ok on this then those bios settings are wrong for your Barton.

 

Check the specs on the PSU and make sure there is enough power on the proper
rails to power you up. It's possible that you are limited to 2 banks of
PC3200 and over. Check the product page and manual. If you have more than
one stick of memory, take one out.

Good Luck

 

Self build is so much more involved than just plugging everything together
;] It maybe goes smooth with automatic configuration for 30% of builds but
it seems there are usualy hiccups to fix. Once you get it booting, then
there is more reading manuals and/or asking/googling advice for decent bios
settings and then the whole thing needs its stability checked starting with
http://www.memtest86.com.
It is pretty involved, busy guys who dont need a new hobby -beware.

Small grace is that when you do get it going, youll have pretty much one of
the fastest socket A systems thats ever likely to be made which youd be
unlikely to get sold premade unless its in premium system.
-Seems you bought pretty good components.

Its not usualy like that, Ive flashed the a7v600's predecessor a7v8x-x a
few times and it keeps the bios settings, the update is for the code only
(not like a total reset). Updating bios while running the athlon 800 might
be the best thing to do first. -funny thing though, a7v600 isnt ~supposed
to support cpus under 1 Ghz :/

Good luck,
pief

 

Most of the answers I got were referring to the heatsink/cooler. And they
were right.
The final solution was simple: turn the heatsink/cooler 180 degrees. It's
asymmetric, but it fits in both ways.
It's pretty amazing that this is possible
And yes, there is some little notice in the installationsguide ("notice that
the clip is not symetrical, it should be right above the die").
So again: RTFM! I did, but not good enough;-(
Hope this might help others when they have the same problems.

Good luck.
René