I've pluged e-pci power cable(6+2pin) to eps 8 pin on motherboard

Solution 1:

From a comparison of their pinouts (image taken from Overclock.net: GPU and CPU power connections):

In theory you should not have been able to fit the connector. From the image above you can see that there are several keying differences between the pins (chamfered edges on the pins) that would have made it difficult to connect an EPS connector to a PCIe on a graphics card, but sadly probably not the other way around. This is something of an oversight in connector design.

The pinouts are effectively opposite. Where one PCIe has the 12V lines on 1-4 (ignoring sense pins), EPS has them on 5-8. What you have effectively managed to do is switch 12V and ground. Definitely not good.

Chances are you have blown out some or all of the power regulators on the motherboard, with possibly more components gone as well. There is nothing you can do without a lot of fault-finding and desoldering components.

Your board is fried. You need to get a new one. It is difficult to know whether your CPU or other components are fried without first replacing the motherboard.