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CPU mbo mismatch?

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February 12, 2009 1:26:53 PM

Had a Dell Dimension 8400 with a runaway CPU fan that would not boot up and decided to build a cheap replacement.
Purchased a Biostar G31-M7 TE 775 mATX mbo (socket 775), Intel Celeron 430-L single core, and the cheapest case I could find. Swapped in a known functioning psu and monitor. Problem I have is I cannot boot-up. CPU cooling fan spins, a hard drive I attached spins, but no video. Also, my USB attached wireless receiver for moue/keyboard does not light. Tried resetting CMOS, triple checking connections, and swapping wireless USB receiver and monitor over to another known working box (to confirm these peripherals work – which they do). This is my first build – what have I over looked? I have no RAM or cards on the mbo, just a functioning psu and monitor attached to a new mbo and cpu.

Only thing I can think of is a mismatch of processor and mbo. The mbo product spec lists a Celeron 400 as being compatible, the one I purchased is a Celeron 430, are these compatible?

More about : cpu mbo mismatch

a b à CPUs
February 12, 2009 2:47:26 PM

I was thinking bios revision could be an issue, but looking at the website it appears that it is supported, and lists no revision from which it is supported, therefore its probably not a bios problem.

Will it boot with no ram (i've never tried)
a b à CPUs
February 12, 2009 2:48:57 PM

if the 3100 is sharing main memory, then attempting to boot without any memory installed would surely result in the 3100 not being able to display anything, which sounds like what you've got...
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February 12, 2009 5:17:46 PM

13thmonkey said:
if the 3100 is sharing main memory, then attempting to boot without any memory installed would surely result in the 3100 not being able to display anything, which sounds like what you've got...



Thanks for the response 13thmonkey,

Yes, I have tried booting with ram installed and received the same results - blank screen. Once one powers up, would you know if any activity is required initially from the CPU, or does the BIOS in the CMOS perform its job prior to a call to the CPU? Could I pull a CPU and get into BIOS in order to rule out a bad CPU?

This is driving me crazy. I started with pretty much a complete system and then starting removing drives, cards, and RAM in order to diagnose this isssue. I dooubt I shorted anything during assembly because I was using a wrist strap.

Any help would be much appreciated.
February 12, 2009 6:05:24 PM

itsbob,

I'm not familiar with that mobo...does it have a setting in the BIOS to change/enable video output? Also look for a BIOS setting for enabling USB.
Did you do a hard drive reformat?
February 12, 2009 6:30:20 PM

CoachB said:
itsbob,

I'm not familiar with that mobo...does it have a setting in the BIOS to change/enable video output? Also look for a BIOS setting for enabling USB.
Did you do a hard drive reformat?


Thanks for the response CoachB,

This is my first build and I may have overlooked something very elementary. Basically what I have done is power up a new mbo and cpu (that are compatible) and have a blank screen so I cannot access bios. I started with a complete system, and starting removing drives, boards and ram in order to diagnose this blank screen issue. The psu and monitor both work on another system I have. Am I suppose to boot off a disk? I thought the cmos on the mbo contained the bios. The instructions that came with my Biostar G31-M7 TE MBO just state to install a cpu, ram, attach power, and after an OS is installed, to install a provided disk that contains more drivers for better system performance. Like I mentioned earlier, I have installed the cpu, ram, and attached power, and all I get is a blank screen. I have consequently removed the ram, leaving just a new mbo, new cpu, and a known working psu and monitor.

Any help would be much appreciated,

Bob A.
February 12, 2009 7:13:41 PM

I think you need CPU and Ram at a minimum to boot. Do you get any beeps when you try to boot? Do you have both the 24 pin and the 4 pin power connectors connected to the mobo? Are you sure the Ram is compatible with this mobo?
One other thing you can try is obtaining a cheap PCI video card and see if you get video that way.
What PSU do you have??
a b à CPUs
February 13, 2009 5:56:31 AM

+1 to both power connectors, its possible that the dell had a non-standard power supply?
February 13, 2009 3:30:59 PM

CoachB said:
I think you need CPU and Ram at a minimum to boot. Do you get any beeps when you try to boot? Do you have both the 24 pin and the 4 pin power connectors connected to the mobo? Are you sure the Ram is compatible with this mobo?
One other thing you can try is obtaining a cheap PCI video card and see if you get video that way.
What PSU do you have??


Thanks again for responding CoachB,

I get no beeps, I have both the 24 pin and 4 pin power connected to the mobo, yes - the ram is compatible.
This may not be the appropriate forum for this but the following is a better documented history of my issue, any help would be appreciated - thanks again:

Had a Dell Dimension 8400 Pentium 4 (purchased 9/2004) with a runaway CPU fan that would not boot up. Found similar issues in a forum with one poster mentioning that 9 out of 10 times the reason is a bad mbo.

Decided to rebuild and go cheap. Due to Dell’s unique mbo form factor, had to purchase a new case (mATX), and bought a Biostar G31-M7 TE 775 mATX mbo (socket 775). Swapped in the Dell 350watt psu, ram, video board, sound board, and drives. Turned on power and no POST, no beeps, and no video – blank screen. cpu fan spins, hard drive spins, but no video and oddly enough, no indication that my USB receiver for my wireless mouse and keyboard is functioning (the receiver should light and that does not occur).

Thought maybe the P4 was bad and purchased an Intel Celeron 430-L single core (socket 775) – same results. Swapped out the Dell psu, and replaced with a known functioning and compatible psu – same result. Iteratively removed ram, video board, sound board, and drives – same result. Anyone know if if is possible to POST with just psu, mbo, and cpu? How about just psu, and mbo? Does BIOS get a call from CMOS without going through cpu?

Only thing I can think of is that when I initially secured mbo to the chassis, I used washers that came with the case that appear to be insulating washers. Could I have shorted the board by doing this? Why is does mbo have to ground to the chassis, isn’t the psu fully grounded through the power cord? I have since removed the washers and the result is the same.

This is my first build and maybe I have over-looked something very elementary:
• Is my mbo and cpu incompatible? (the mbo states that it supports a Celeron 400 – I have a Celeron 430-L)
• Is BIOS already loaded in CMOS on new mbo’s?
• Should I somehow be booting up off a disk?
February 13, 2009 3:34:02 PM

13thmonkey said:
+1 to both power connectors, its possible that the dell had a non-standard power supply?


Thanks for responding 13thmonkey,

Yes I beleive Dell may have used proprietary psu's during the 90's, but the Dimension 8400 psu I am using is from 2004. I also swapped in another psu I have that is a known functioning and compatible 250w psu and I get the same results - no post, no beeps, no video.

Thanks.
a b à CPUs
February 13, 2009 4:19:24 PM

I assume that you have connected up the case switches etc. to the headers on the mobo correctly, you might get a similar result from attaching the reset switch to the power switch header on the mobo as it doesn't lock.

So check that you've got the right leads plugged into the right headers.


February 13, 2009 6:58:29 PM

itsbob,

From what I can find on the internet, that mobo does support the Celeron 430-L.
The mobo comes with a default BIOS/CMOS program on the BIOS chip. That program allows you to POST so that you can begin configuring your system. You should be able to POST with CPU, Video Card & Ram.

Here is a long shot....check the jumper on the BIOS reset pins. I remember an issue with new boards arriving from the factory with the jumper in the clear position.
Wouldn't hurt to (1) unplug PSU, (2) remove mobo battery, (3) place jumper in clear position (consult manual), (4) wait 10 minutes, (5) replace battery, (6) place jumper in run position, (7) plug in PSU. Cross your fingers.

If this doesn't work try assembling system outside of the case on a cardboard box or phone book. This will rule out a grounding issue.
February 13, 2009 7:19:37 PM

Thanks for the research CoachB, I will try resetting the BIOS again according to your suggestion. Would you happen to know if ram is needed to POST. I have tried powering up with just a psu, mobo, and cpu but get the same no POST, no beeps, and no video. I also noticed that my ram speed is 400MHz and the mobo has a data bus speed only as low as 533MHz. I just found this info in a book:

"Incorrectly set memory timing parameters in BIOS may prevent the machine from operating at all. Some systems with intel chipsets, when presented with out-of-bounds memory timing parameters during POST, simply lock up. This happens before video or any other devices are initialized, so the machine appears totally dead. Using the jumper to clear the CMOS to default is frequently the only rememdy."

Unfortunately, I have reset CMOS per the mobo instructions many times with the same results. I'll try your way though.

Thanks,

itsbob
February 13, 2009 11:32:44 PM

Ok, we need to know the brand, speed, size, and if possible, model number of the Ram you are using. If you do indeed have 400Mhz Ram that would be a problem as the motherboard supports 533Mhz or higher only.
Fortunately, if that is the problem it is an easy and inexpensive fix. DDR2 ram is pretty cheap right now. You might even be able to return the 400 stuff and swap for 533.
February 13, 2009 11:44:09 PM

I was looking at the picture of this model and noticed a 4pin power connecter near the i/o sheild. Does this board require 2 power hookups?
February 14, 2009 12:18:14 AM

Hey itsbob. Sorry to hear you're having so much trouble. I feel partly to blame. I'm the author of the post you ran across, and you even purchased the mobo I recommended in that post. I must have neglected to think of the possibility that Dell only shipped PC3200 DDR2 ram with the Dimension 8400. Granted, the 8400 is a pretty old computer, but PC3200 DDR2 ram was so short lived, I never stopped to think that the 8400 ever shipped out with that poky memory. It sounds like the main culprit is that old ram. I suggest taking this opportunity to upgrade your memory.

If you don't care about dual channel mode and want 1GB of memory (with easy updrade to 2GB in the future):
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If you want 1GB of memory and want dual channel mode:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If you want 2GB of ram right now, or if you want some DDR 800 ram for overclocking headroom:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

BTW, in order for your computer to boot, it must AT LEAST have the following installed on the motherboard: CPU, RAM, video of some sort (either integrated or a graphics card), and the two power plugs plugged into the motherboard (the square 4 pin plug and the 24 pin plug).
February 14, 2009 12:31:14 PM

CoachB said:
Ok, we need to know the brand, speed, size, and if possible, model number of the Ram you are using. If you do indeed have 400Mhz Ram that would be a problem as the motherboard supports 533Mhz or higher only.
Fortunately, if that is the problem it is an easy and inexpensive fix. DDR2 ram is pretty cheap right now. You might even be able to return the 400 stuff and swap for 533.



Thanks CoachB, I think you and joefriday nailed it. I am off to buy compatible ram. I was using Infineon's DDR2 SDRAM #HYS64T64000HU-5-A, rated 400MHz. This speed is slower than the minimum my mobo states (533MHz). I initially thought that this mismatch would just slow things done. Didn't realize timing came into play, though why during POST, no error beeps?

Thanks again.
February 14, 2009 12:32:57 PM

joefriday said:
Hey itsbob. Sorry to hear you're having so much trouble. I feel partly to blame. I'm the author of the post you ran across, and you even purchased the mobo I recommended in that post. I must have neglected to think of the possibility that Dell only shipped PC3200 DDR2 ram with the Dimension 8400. Granted, the 8400 is a pretty old computer, but PC3200 DDR2 ram was so short lived, I never stopped to think that the 8400 ever shipped out with that poky memory. It sounds like the main culprit is that old ram. I suggest taking this opportunity to upgrade your memory.

If you don't care about dual channel mode and want 1GB of memory (with easy updrade to 2GB in the future):
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If you want 1GB of memory and want dual channel mode:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If you want 2GB of ram right now, or if you want some DDR 800 ram for overclocking headroom:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

BTW, in order for your computer to boot, it must AT LEAST have the following installed on the motherboard: CPU, RAM, video of some sort (either integrated or a graphics card), and the two power plugs plugged into the motherboard (the square 4 pin plug and the 24 pin plug).


Thanks joefriday, I think you nailed it. I am off to buy compatible ram as you mentione in your reply. I was using Infineon's DDR2 SDRAM #HYS64T64000HU-5-A, rated 400MHz. This speed is slower than the minimum my mobo states (533MHz). I initially thought that this mismatch would just slow things down. Didn't realize timing came into play, though why during POST, no error beeps?

Thanks again.
February 14, 2009 1:10:55 PM

I've found error beeps to be highly variable. For example, on an OLD i810 socket 370 motherboard I have, it would always beep when there was an incompatible stick of memory. On the other hand, a socket AM2 motherboard I have will never beep. When I first put the AMD computer together, I would get a situation similar to yours: fans on, but no video output. After looking over everything very closely, I realized that one ram stick was not pushed down all the way. Reseated the ram, and bing, it posted and no problems since. Whether or not you'll ever hear the mobo beeping is a crapshoot.
!