Galaxy Tab P1000 shows a phone  PC symbol and is not responding after flashing I was flashing my GT P1000 and the power went down, then on the galaxy tab screen i see an image of a Phone ! PC and nothing i can do to reboot it or connecting it to the laptop. Its dead. 

please help
The best you can do is power off the device completely, but do nothing for now, head over to samfirmware and download the appropriate ROM for your region. 

Once you do that, refer to the instruction on using Odin.

You should have the PIT, and the MD5 file, and also the CSC file set up within Odin.

Then press and hold the VOLUME DOWN button, and then briefly press the POWER button, the device should go into download mode. From there Odin should detect the device, then start flashing as normal.

Disclaimer: 

I am not responsible, please double check to make sure you have the right check-boxes ticked within Odin. If all else fails, refer to the XDA forum

Another route:

If you cannot get into Download mode, try the hard reset - that is, ensure the tablet is powered off completely, hold the VOLUME UP button, and then briefly press the POWER button, the device should hard reset itself. 

And try the above again.