Figure this one out.... What the heck?!?!

[100Core]

Hello All,

I have run into what I think is a pretty bizarre issue. Hopefully someone can help me with this one.

Ok, I was building a new build for a friend, and the rig refused to post, powered on fine, all fans spinning... but no beeps, and no video feed.

I replaced the components one at a time to isolate the problem
Switched out the:

memory
motherboard
video card
power supply

All with no luck....

Finally, I switched out the processor... and it popped right on!!

So I concluded that it was a bum processor....

Until I put the same bum processor into a different rig, and everything worked perfectly!!!!


Some info that may or may not be relevent:

I thought that maybe the processor was just set incorrectly when it wasn't working... I disproved this by trying it several times

The non-working (or half-working) proceesor is a Dual Core Pentium D 920

The non working rig (working after switching the processor) worked when I put a Q9550 in it

The mobo is brand new, and is set to all the original settings



I will be diligently watching this thread, so if any further info you think is neccesary, I will provide it promptly

Thank you for any help!! This is an enigma well over my head!!

 

[Idontcare]

Finally, I switched out the processor... and it popped right on!!

*snip*

Until I put the same bum processor into a different rig, and everything worked perfectly!!!!

*snip*

The mobo is brand new, and is set to all the original settings

Do you have positive confirmation from the mobo maker that the mobo/bios does in fact support the specific processor you are having trouble with?

I would not just assume new mobo has backward compatibility with all older socket-compatible processors.

Even if the website lists it as compatible my first checklist item would be to email their customer support and get confirmation from them that the cpu/mobo combo is known to be functional (versus just expected to be functional but no one has ever tested it to find out).

At this point I would say you still haven't determined whether the source of the imcompatibility problem is the mobo or the cpu.

 

[100Core]

Well,

Both the CPU and the mobo are 775 socket. Is this not enough to confirm compatability? Admittedly, it is an older dual core, but not that old!

I will indeed email customer support for my mobo...


Other ideas? Or can someone confirm that this is probably my issue? Anyone ever experience same-socket combos not working?

Thank you for caring IDontCare!!

 

[VirtualLarry]

Both the CPU and the mobo are 775 socket. Is this not enough to confirm compatability?

Sadly, no it's not.

A lot of the newer boards don't support the older CPUs, and of course, the older boards don't support the newer CPUs. 775 isn't universally compatible.

 

[100Core]

Wow.. That's bogus.

Guess you gotta learn the hard way sometimes.

So it's sounds like that must be it based on the symptoms.

Thanks for the help!

Now... off to buy a new processor, awesome

But not before checking my mobo's compatability info!!

 

[Duvie]

sounds like the type of things that happen with an incompatable microcode....I remembered some things like this with early wolfdales on older boards. You had to have an older chip to post and flash the mobo to the newer bios the boards were not shipping with. It would do the same things you stated...



Have you tried to look at some of the older bioses or beat bioses for that board. Maybe someone has dealt with this and worked on a fix.

 

[aigomorla]

Bios updates...

Check motherboard vendor website and see if theres a bios update, b4 u wait on the email at tech support telling you, you might need a bios update.

 

[Lemon law]

Bios updates...

Check motherboard vendor website and see if theres a bios update, b4 u wait on the email at tech support telling you, you might need a bios update.
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I agree and bingo aigomorla, step one is always checking your Mobo makers web site to see the cpu compatibility list.

In the case of my wife's computer, I am thinking of upgrading to a e5200 cpu, which will not be supported by the board's existing bios version, but the e5200 will be supported after a bios update. Its all there on that board cpu compatibility list but not there in the printed manual that came with the mobo.

 

[davidrees]

why is it that the weirder the problem, the less likely people are to post specific details?

 

[lopri]

Weird indeed. I thought backward compatibility was a non-issue on LGA775. I had an old Celeron that I kept as a backup CPU for quite a while and it worked for all boards I had tried. I think it's Cedar Mill variant but I could be wrong, it's a pre-Conroe CPU for sure, though. Try flashing to a newer BIOS?

 

[Denithor]

why is it that the weirder the problem, the less likely people are to post specific details?

Word.

Give us the motherboard model & maybe we can be more helpful.