Flex&QuartusⅡVer9.0 [JTAG chain problem detected]

Hello,

Please refer to attached file.

I have a FlexSeries[EPF6024AQC240-2&EPC1441PCB] on Board,USB Blaster,Quartus software Ver9.0,Install Program[pof file&sof file]

And I want to Install Program file to [EPF6024AQC240-2&EPC1441PCB].

But appear error.

Error:JTAG chain problem detected

Error:No device detected

Error:The TD0 connection to the download cable might be shorted to GND or is an open circuit

Error:The TCK and TMS connections to the last device might have problem

Maybe It's in the state that ,can't communicate.

Is special setting needed there?

Please give me your advice.