New Asus P4U800-X Motherboard won,t post

What core is the CPU?  Willemette?  What's the Asus board's chipset?  Intel 865 or newer?  I had an 865 chipset and a willemette processor - I found out the 865 chipset isn't compatible with the Willemette core CPU.  You might need a different CPU.

Thanks -= the Mobo Chipset is ULI M1683  supporting 800 FSB and supports all P4 processors according to Asus support site - problem with power switch seems to indicate mobo problem - but I am really no expert

Many mobo's needs > 5 sec push on the power switch to "force power down".

things to check:

ATX12 volt connector (4pin  square connector powers CPU)

Clear CMOS with jumper

CPU fan to correct connector on mobo(senses fan rpm, otherwise CPU shut down)

next thing will be to remove mobo from case put on some non conductive material (wood /cardboard)

only insert
CPU with cooling
1 stick of RAM
GFX card
keyboard

hook up power supply
and short the two pins on mobo hooked to your power switch(start button)

 

 

>and short the two pins on mobo hooked to your power switch(start button)

You just need to touch the pins not a permanent short
and do hook up monitor as well

Many ASUS boards have a voicefeature telling boot faults this off couse needs a hooked up speaker

Thanks - I've held down the power switch for longer than 5 secs to power off - didn't work , pressed reset switch  - didn't work, - Cleared CMOS with jumpers, Mobo is receiving 12v, -12v, -5v,  5v  tested with P0050 POST CARD tester - the Reset light (LCD) on the tester shows on all the time indicating a power loop, the BIOS light and Run light fail to work. The tester seems to indicate that the board is receiving the power but that the circuit for the reset switch is permenently powered on. I'll try removing the Mobo and testing as you indicated. Cheers

Carried out test as suggested - CPU fan powers up mobo LCD lights up - no post

A short in the power or reset button will upset the Mobo

hope you will find a simple casing fault and get your backup going

How about removing the wires to the reset pins ?

Cheers - the out of case test seems to eliminate the switches

Sorry did'nt see your last post

did you check that

ATX12 volt connector (4pin  square connector powers CPU) ?
Fan will run independantly of this, but CPu will not

And also the switch wires - shorting the switch contacts for both power switch and reset switch

??

What is best way to test CPU power?

So your Mobo is having an "out of case" experience: ^o^

>And also the switch wires - shorting the switch contacts for both power switch and reset switch

< what do you mean ??

> What is best way to test CPU power?

simplest way is to feel if heatsink gets warm, mind your fingers with the fan

With a DC voltmeter set to 20v range I get a reading of 0.17 across the black and yellow connector pins

Hey Wiggielodge1

did you check that

ATX12 volt connector (4pin  square connector powers CPU) ?
Fan will run independantly of this, but CPU will not

check the lower picture

http://www.anandtech.com/guides/viewfaq.html?i=119

Yellow is + 12 volt
black is ground
red is +5 volt
orange is 3,3 volt(afair)

> With a DC voltmeter set to 20v range I get a reading of 0.17 across the black and yellow connector pins

It seems you dont have 12 volt there

where is that measured ?

The heatsink does not appear to heat up

No not with 0.17volts

Hey to summarize

Things you did not answer

1)
CPU fan to correct connector on mobo(senses fan rpm, otherwise CPU shut down, no 12 volt in 4 pin connector)

2)
ATX12 volt connector (4pin  square connector powers CPU) ?
Fan will run independantly of this, but CPU will not

check the lower picture

http://www.anandtech.com/guides/viewfaq.html?i=119

3)

> With a DC voltmeter set to 20v range I get a reading of 0.17 across the black and yellow connector pins

Where did you measure that

because fans also operate at 12 volts and they spin

please answer /check these things

Thanks for sticking with me on this - its the first time I've used a forum I do appreciate the help
To deal with the summary points
1. CPU fan connector wire correctly connected

2. ATX 4 pin connector properly connected ( it was across the black and yellow pins on this that I got the 0.17 reading

While I do generally consider ASUS a quality company, the company I got my board from listed in their manual all CPUs from 1.6 to 3.2+ GHz were supported - but that was false.  At least, it was wrong of them not to point out the Willemette Issue.  I'm not familiar with your chipset, but I'd try contacting Asus to verify compatibility - I searched with google and found very little info on the chipset.  I then downloaded the manual for your mobo and could find no reference to the Willamette core.  Email Asus support and double check.  If you can, try a newer CPU in the system and see if that works.

Can you measure if you get 12 volt shortly, when starting the pc ?

Access to spare PSU ?

LEEW

Do you think an unsupported CPU will prevent 12 volt in the 12 volt ATX connector ?

supported cpu's
P4-1.8A GHz (Socket478, 400 FSB, L2 cache:512KB) 1.07  1004  being northwood  
P4-1.8 GHz (Socket478, 400 FSB, L2 cache:256KB)                    being willamette

so ASUS states that willamette is supported

http://www.asus.com.tw/support/cpusupport/cpusupport.aspx?ModelName=P4U800-X

being in the CET timezone it's bedtime now

But I guess it is obvious you are missing 12 volt from your PSU

Thanks mate have a good night

Hey Wiggielodge1

Any progress ?

Hey Stockhes

Current Situation

Motherboard out of case, test for all voltages correct { using P10050 post card ) Power switch works O.K. 5 sec powerdown, Reset switch works LEDs on Test Card but has no effect on mobo power. No POST no bleeps

I feel that I have a DOA motherboard but want to make sure sure I've eliminated as many possible other alternatives before RMA

That means you have 12 volts in 4 pin connector ?

If you don't you wont post to bios !

Many people thinks the mobo can post to bios by itself, but it needs the cpu and ram to process the bios information

voltage test will be correct if the 12 volt wire in ATX AUX connector delivers the juice, but that won't help your CPU, because its solely powered by the 4pin connector.

With ATX power supply connected on both connectors (incl 4 pin to Mobo) 4pin tests at 12.7 v black/yellow on each pair So power for CPU is Ok and fan works but unable to detect heat in the cpu heatsink. Cpu worked fine in anothermobo couple days ago.

Then its probably not a voltage issue.

Can you exchange the RAM-stick with a proven one or try the current one in another machine ?

Fitted newDDR400  512 ram stick  in each of slots no post no beeps
substituted for 512 PC2100 ram tried in each slot  no beeps no post

using P10050 post card tester get error code 80 on led display  = the keyboard test has started

That post card tester is it displaying hex or decimal ?
Because 80 decimal ~ 50 hex
80 hex is reserved and 50 hex is initialize USB

But now that it might not be a power issue all is open again.

I just saw at H'7F it will report errors and await keyboard input, what if you press F1 and check if anything happens on post card.


Which GFX do you have ?

Hey Wiggie

Please note that GFX with AGP spec 2.0 or above is needed for this mobo

AGP 1.0 AGP 1x&2x@3.3volts
AGP 2.0 AGP4X@1,5 volts
AGP 3.0 AGP8X@0.8 volts

AGP2 & 3.0 can mix so you can run 8X @ 1,5 volts

GP7 440TL  8X 64M Graphics card - The issue seems to reside in the fact  - No Beeps  - No Post

There ya go! Appreciate the help

Wiggielodge1,

No comment has been added to this question in more than 21 days, so it is now classified as abandoned..
I will leave the following recommendation for this question in the Cleanup topic area:
Accept: stockhes

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Rindi
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