Error: Can't access JTAG chain

There can be a lot of reasons. Power supply, unconnected pin, missing pull-up... You can start with the JTAG chain debugger (described on pages 20-20 to 20-29 of the programmer datasheet (http://www.altera.com/literature/hb/qts/qts_qii53022.pdf)).

If you can't access the JTAG chain, the primary reason could be connection problem or no power detected on the JTAG chain. Please check your JTAG header pins (and possibly connections). You might have mistakenly misplaced them.

you can also check with your blaster. try changing it and configuring with new blaster. sometimes the buffer inside blaster damages which might cause this error.

the same problem is trouble me too，but when i check my quartusII 9.0, i haven't find JTAG debug tools under the tools menu。can anyone help me pls！

Tools > JTAG Debug tools was introduced later in 10.0

Zhang, in Quartus 9.1 the JTAG debugger is not under Tools; it is under Processing->JTAG Chain Debugger. This is the menu of the Programmer tool, not the main Quartus window. Hopefully it is there in 9.0 as well.

HI ,the same problem puzzled me now, and i don't know where the wrong is. The pcb is also a finished product,when i download the program by jtag, it gives the error "can't access the jtag chain"

Even with no clock at all, the FPGA should respond on the JTAG connection. The problem is probably somewhere else that the crystal. Check the power supplies, ground connections, impedances on the JTAG lines, etc... Check also the JTAG signals with a scope, especially the clock that is often the source of JTAG problems.

Hii here is my pcb