If your DSP-4x00 CableAnalyzer does not reboot correctly after a software update, there is a back door feature you can try. (We regret to say we are no longer able to offer calibration and repair for the DSP-4x00 CableAnalyzer. It has been replaced with the DSX CableAnalyzer.)
With the DSP-4x00 CableAnalyzer powered off, hold down the F4 key and the Backlight key. Keeping those keys pressed down, rotate the dial to AUTOTEST. You will hear a brief beep from the DSP-4x00 CableAnalyzer. Let go of the keys.
In LinkWare, click on Options > Serial Port and select Slow:
Click Test Connection to verify the DSP-4x00 is talking to LinkWare. Then go ahead a repeat the update process. This will take some time since the communication speed is now set at Slow (38,400 Baud).
If this works, don't forget to set LinkWare back to Fast on the Serial Port options.