Is This Mobo or CPU Broken?

  • Thread starter Thread starter Pete
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Pete

I have a barebones to which I carefully added a CPU & memory.

Sadly something is wrong.

None of the motherboard controlled fans spin. I can hear the power
supply & HD spining. I get nothing out on the monitor and no beep
codes from the BIOS to say there is a problem.

The barebones is wired up exactly as it came out of the factory and
everything including video are onboard.

Everything I can check has been double checked. Wired up as per the
manual. FAT32 HD works in another system as does floppy, memory sticks
and CD drives.

I put in a 'new' CPU that I am told was tested working before I got
it. (perhaps this is the problem??)

If I press the reset button I can hear the HD restart whiring but
thats all.

I can use the electronic switch at the front to switch the power on
and off and when if goes off both the case and cpu fans move (jerk)
very slightly but that is all.

I removed the CPU and memory to see if the machine would post without
them but it seems not.

Even without a CPU in wouldn't at least the case fan spin (controlled
from mobo)?

Any ideas?

I was told the barebones was new when I bought it but am not so sure
now as the seller let slip via his last e.mail he had flashed the
BIOS...!

Main Question is: Will a motherboard boot at least to BIOS without
memory or CPU?


Pete
 
Main Question is: Will a motherboard boot at least to BIOS without
memory or CPU?
Click to expand...


you need a cpu and memory to post...

however with a cou in the machine and no memory
you may at least get an error code (beep)
 
Pete said:
I have a barebones to which I carefully added a CPU & memory.

Sadly something is wrong.

None of the motherboard controlled fans spin. I can hear the power
supply & HD spining. I get nothing out on the monitor and no beep
codes from the BIOS to say there is a problem.

The barebones is wired up exactly as it came out of the factory and
everything including video are onboard.

Everything I can check has been double checked. Wired up as per the
manual. FAT32 HD works in another system as does floppy, memory sticks
and CD drives.

I put in a 'new' CPU that I am told was tested working before I got
it. (perhaps this is the problem??)

If I press the reset button I can hear the HD restart whiring but
thats all.

I can use the electronic switch at the front to switch the power on
and off and when if goes off both the case and cpu fans move (jerk)
very slightly but that is all.

I removed the CPU and memory to see if the machine would post without
them but it seems not.

Even without a CPU in wouldn't at least the case fan spin (controlled
from mobo)?

Any ideas?

I was told the barebones was new when I bought it but am not so sure
now as the seller let slip via his last e.mail he had flashed the
BIOS...!

Main Question is: Will a motherboard boot at least to BIOS without
memory or CPU?


Pete
Click to expand...

You mention in your post, that the power supply fan is spinning
and the hard drive appears to spin. But you also mention getting
the "twitch" response from the CPU fan and case fan. Those results
aren't consistent with one another, in terms of powering. Generally,
fan power should be available immediately, as soon as there is +12V.
Your hard drive uses +12V, and the fan spinning means the power
supply has been turned on. Fan header power comes through the
20 pin power cable. Are both the 20 pin power cable and the
2x2 ATX12V processor power cable, depending on what kind of
product this is, connected ? Make sure both power cables are
seated and the nylon latch is engaged on each.

If the BIOS chip was erased by the previous owner, there is nothing
for the processor to execute. It would be hard to programmatically
make a beep sound, with no code to execute.

1) Check both power cables.
2) Recheck your assembly.
3a) If you can get the CPU fan to spin, and the case fan,
and you are still not getting a POST, you might consider
going to badflash.com and buying another flash chip with
a BIOS programmed in it for your product. There are
a number of companies who offer that service, and should
do it for less than $25.

or

3b) Send this bargain, back to the seller.

If the BIOS contents are valid, a CPU and no memory will beep.
A CPU plus no video card will beep. If there is no CPU, there
is nothing to execute code. A memory, a video card, and
no CPU, will behave like a lump of coal.

Depending on the (unstated brand/model of product), there can
be other debugging devices in there. Asus puts Vocal POST on
some of their boards. Other companies put a 2 digit LED
display. Still others use separate LEDs to display diagnostic
info. All of these can be supplements to the beep code.
You can also purchase a PCI POST card (with 2 digit LED
display on it), to see if any code is being executed.

Paul
 
I have a barebones to which I carefully added a CPU & memory.
Click to expand...

Which barebones?
Which CPU?
Which memory?
Which motherboard?

These are fairly important details.

What's the history of these parts, which (if any) were
previously seen working, can be reasonably assumed viable?
While a new CPU might be assumed viable (unless from a
questionable source like ebay), a motherboard, especially a
lower-end model often included in some barebones, might most
need confirmation of viability... which of course you're
trying to do, but with any suggestion we make, IF the parts
don't end up working then it's a matter of odds which should
be retried or replaced and without more detail it's
difficult to lay odds.

Sadly something is wrong.

None of the motherboard controlled fans spin. I can hear the power
supply & HD spining. I get nothing out on the monitor and no beep
codes from the BIOS to say there is a problem.
Click to expand...

Check power supply and battery voltages (with a multimeter).
Make sure there are no case standoffs in the wrong place and
thus shorting out the motherboard, or is the board not cased
up yet? If sitting outside of the desk make sure it's not
on an anti-static surface.
The barebones is wired up exactly as it came out of the factory and
everything including video are onboard.
Click to expand...

Double-check all the possible configurable options (like
jumpers) by comparing it to the manual.

Everything I can check has been double checked. Wired up as per the
manual. FAT32 HD works in another system as does floppy, memory sticks
and CD drives.
Click to expand...

Disconnect all these things and only put the CPU, 1 memory
module, and onboard video. No drives, no keyboard or mouse,
etc... goal at this point is only to get system to POST,
then proceed to reconnect things later. Disconnect the
front panel switches and LED wiring and turn it on by
shorting the two power-on pins together carefully with a
conductive object like a screwdriver tip.

I put in a 'new' CPU that I am told was tested working before I got
it. (perhaps this is the problem??)
Click to expand...

I hope you put a heatsink on it, and confirmed the heatsink
was properly installed such that it makes good contact with
the base. For a few dozen seconds of trial it isn't
significant whether the fan spins, it will not have
overheated onto the point of damage within that time but if
you continually retry it, touch-test the heatsink
periodically to be sure this isn't progressively overheating
it (heatsink HOT).

If I press the reset button I can hear the HD restart whiring but
thats all.

I can use the electronic switch at the front to switch the power on
and off and when if goes off both the case and cpu fans move (jerk)
very slightly but that is all.
Click to expand...

We really need a complete description of the parts,
including the make, model, wattage of power supply.
Consider that these specific parts are the issue since other
parts/systems work, the devil is in the details.

One random possiblity is that this barebones has a junk
power supply that is simply inadequate for the system,
though we would hope such a problem would be uncovered
quickly by the seller since it was a kit including both the
board and PSU, yes?


I removed the CPU and memory to see if the machine would post without
them but it seems not.
Click to expand...

It definitely would not, these two are always required as is
video but since video is integrated...

Even without a CPU in wouldn't at least the case fan spin (controlled
from mobo)?
Click to expand...

Not necessarily, if the motherboard logic is controlling it
rather than the older type of directly-wired power through
the motherboard from PSU... which in some cases is more
reliable... progress has it's costs.

Any ideas?

I was told the barebones was new when I bought it but am not so sure
now as the seller let slip via his last e.mail he had flashed the
BIOS...!
Click to expand...

Ask "why" bios was flashed. Could be a preventative measure
if sell had had other buyers try to RMA a board after a
fluke bios flashing mishap or maybe the board needed it to
support the CPU, but it would be good to know this.

Main Question is: Will a motherboard boot at least to BIOS without
memory or CPU?
Click to expand...


Never. Without one or the other it might beep though, if
you hear beeps then see if you can decipher a code from them
but some beeps like "no memory" are generic and obvious if
you have no memory installed.

Strip system down to bare minimum as mentioned initially and
disconnect AC power to PSU then use the clear CMOS jumper
(or remove battery for 10 minutes) then retry it.
 
Which barebones?
Which CPU?
Which memory?
Which motherboard?
Click to expand...

Sorry for delay in responding. Especially as the responses were very
helpful.

The system is a KLOSS (LGA775. Proprietary Intel board.) but as
virtually no one knows anything about these systems I was looking for
a more generic response.

I've put up another question about "mobo solder discolouration" but at
the moment I am waiting on an independent test on the CPU & for a
power tester to arrive..

Anyway. Cheers for responses.

Pete
 
Sorry for delay in responding. Especially as the responses were very
helpful.

The system is a KLOSS (LGA775. Proprietary Intel board.) but as
virtually no one knows anything about these systems I was looking for
a more generic response.
Click to expand...

Unfortunately, with a proprietary board a generic response
might be all the less applicable. Besides measuring the
power levels with a multimeter you might be left swapping in
known good parts, or rather, swapping in these questionable
parts one at a time into a compatible
system/bench-setup/etc.

"Odds" are the motherboard is the problem, power 2nd (since
it can be checked with mutltimeter) and CPU a distant third,
possibly even less likely than a memory incompatibility.
 
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