if unplug the parallel wire of front panel, will the machine fail on self test

[youxiaojie]

dear friend,if we unplug the parallel, will machine stop at test failed step? I don't know it is my mother board damaged or front panel damaged. machine has problem of round reboot when I plug front panel, unplug keyboard, the machine can boot to diagnosis ui and show fail ++ front panel .how can I decide mother board broken or keyboard damaged. thanks. my oscilloscope is 754D.