Trouble programming Cyclone III with USB Blaster (Can't recognize Silicon ID)

[Altera_Forum]

I was able to Program/Verify my FPGA many times until my PC crashed this morning while programming.  

 Since then I'm unable to successfully program, erase or verify.  I get the following message if I try to erase:  info: started programmer operation at mon may 10 16:20:32 2010 info: device 1 silicon id is 0x14 info: erasing asp configuration device(s) error: can't recognize silicon id for device 1 error: operation failed info: ended programmer operation at mon may 10 16:20:32 2010  And if I try to program/verify:  info: started programmer operation at mon may 10 16:34:00 2010 info: device 1 silicon id is 0x14 info: erasing asp configuration device(s) info: programming device 1 info: performing verification on device 1 error: verification failed for device number 1 error: operation failed info: ended programmer operation at mon may 10 16:34:46 2010 Since it "sees" the proper silicon ID, I figure my connections to the device are still in good shape, but why could the verification fail, and is there any workaround (programming without verifying doesn't work).   I've tried rebooting my PC, my board, changing USB port, powering down/up my board, and I still cannot get it to program.  Any lead on this would be greatly appreciated. Thanks!

[Altera_Forum]

Hi, 

To be honest I don´t have an answear for you, but since you haven´t gotten a reply I´ll throw in a few things that i would try..   Firstly have you managed to fix the problem?   If not then, Do you have another setup/board on which you can try to configure from the same PC?   Are you able to configure via JTAG?   Can you try configuring with a different USB balster cable?   What were the circumstances of the PC crash? Anything serious like power surge or something?   I know I´m shooting in the dark a bit. Let us know how you get on.   Good luck

[Altera_Forum]

Unstable operation of the JTAG interface is usually caused by signal quality problems, particularly related to TCK. The problem even existed with some development kits and should be assumed as a likely reason with your own hardware design.

[Altera_Forum]

Thanks for your input. 

 After working on this for a couple days, my conclusion is that my EPCS has gone into lock mode when my PC crashed.  My only connection to the EPCS is through my USB Blaster, so I wasn't able to unlock it yet. However, I managed to get another board, where the same *.pof with my USB Blaster cable for the same device seems to be working just fine.