jinxy said:
Did you try to clear CMOS and than click to save BIOS default on exit
from
I can't get into bios screen. I would think that removing the battery
would reset the bios to default settings, is that not correct? Tried
restarting and tapping F2 and F8, no go.
Am starting to think that this board may truly be dead.
What would lead you to think that the CPU was at fault? I will pull
the CPU, regrease and reseat, and see what happens.
Anyone else with a possible solution , please feel free to jump right
in.
-J
To troubleshoot, you can use the computer case speaker.
First of all, you need to verify whether the motherboard has something to
emit "PC beep". On my computer here, near the front of the case is a small
speaker (like something you'd see in a transistor radio). The other way they
do the "PC beep", is a piezoelectric device soldered to the motherboard
itself. It might be black in color, maybe the diameter of a 25 cent piece.
If a piezo is used, there won't be a speaker in the computer case for that
purpose.
If the computer uses a separate speaker, you'd want to verify the speaker
is connected to the PANEL header. You need that speaker for the next test.
OK, now power off the system (unplug), unplug all the RAM, place the RAM
in antistatic bags for storage. Now, turn on the computer. Does the computer
give a repeating "beep" error code ? If so, that gives you some encouraging
results. To make the beep sound, the processor had to run, it read some
BIOS code, and upon finding no RAM sticks present (by probing SMBUS),
it will beep. That tells you that a lot of the motherboard is working.
In that case, if "RAM installed" = nothing, and "RAM removed" = beep,
it means there is bad RAM in the low memory area (below 640KB). Trying the
RAM sticks one at a time is an alternative. Or swapping in some other
RAM for testing, is an alternative.
If the motherboard still doesn't beep, it could be processor or
motherboard. You would verify the ATX12V 2x2 square connector is
plugged in. (Most recent boards will use that. My old A7N8X-E
ran from +5V, and got the processor power from the main power
cable. But many other boards use the 12V separate cable.)
On the motherboard, the fault could be the BIOS chip. Perhaps
the BIOS code is corrupted. That will give you a black screen.
You'd need programming facilities, to reprogram the chip outside
the motherboard.
Knowing something of the history of the system ("we had a lightning
storm" or "I smelled something funny coming from the power supply"),
can also help you narrow down the fault type.
You can either test the power supply, with a home made load tester.
While the supply is connected to a load, short PS_ON# to an adjacent
COM pin, to turn on the supply. The fan should spin. Using a multimeter,
you can check the main voltages, like 3.3V, 5V, 12V and so on. Also
check for the status signal from the power supply, that says Power_OK.
Even if the supply delivers all good voltages, without a valid status
signal, the motherboard won't start. The motherboard can only
start, when all status signal(s) are valid. The motherboard itself
generates its own internal status, and that is all tied into the
"releasing reset" logic.
HTH,
Paul
