Nahkri wrote:

I have this board,revision 2.0,after i switched the cpu from a Pentium D 805 to a Core2Duo 6600(the board support this cpu),the […]
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I have this board,revision 2.0,after i switched the cpu from a Pentium D 805 to a Core2Duo 6600(the board support this cpu),the board start to act strangely.
It restarts it'self 3 times with the core 2 duo,before it goes into full boot and working corectly.
If i restart the pc from windows it restarts corectly.
I only get this problem if i turn off the pc and then start it again.

This is typical for bad caps.

The Core 2 uses lower voltage so it probably needs a bit more current eventhough the Pentium D needs more power.

Edit

On second thought Kamerats hypothesis is more likely as with bad caps you often (but not always) need to reset manually two or three times to get a post when doing a cold boot.

Maybe it's a way for the motherboard to boot with the right FSB as the i865G chipset doesn't support 1066MHz officially?

Kamerat wrote:

Maybe it's a way for the motherboard to boot with the right FSB as the i865G chipset doesn't support 1066MHz officially?

This is the normal behaviour with P35, P45, X38 and X48 when overclocking but I have never seen it with i865, I think you are correct though.

I have the same MB with the same CPU and I don`t have any issues. I use lastes BIOS version

I have the same mobo with a Core2 Duo 7400, it takes a loong time to boot but apart from that doesn't do anything strange; try upgrading to the latest BIOS.

I checked the caps,they look alright.
The bios i use is the latest one i could find on asrock site.
I checked the board with a couple of socket 775 cpus:2 single core pentium 4 and a core 2 duo e 7400.
With the pentium 4s everything is ok,with the core 2 duo it acts the same.

shiva2004 wrote:

I have the same mobo with a Core2 Duo 7400, it takes a loong time to boot but apart from that doesn't do anything strange; try upgrading to the latest BIOS.

During that long time it takes to boot,can u hear the optical drive spin up and down a couple of times?

No, it doesn't. There is no restart, simply the motherboard takes a little longer than usual to initialize.

I wonder if it could be psu related ?the psu on the pc is a 300w FSP psu.

I had a 775i65G r2.03 a few years ago. After experimenting with a Core 2 X6800, I decided to use a 800 MT/s CPU instead and settled on a Pentium Dual Core E5700 "Wolfdale" CPU. It worked well with that CPU. The board does behave strangely on boot with a 1066 MT/s CPU.