I have pub but no pc for it unfortunately. Assuming you laptop is good, your cable is good, what you can try is via device manager etc is go to comm1 and change a setting and try an upload. The easiest setting to know if it is correct is the baud rate. Make sure comm1 is identical to what is listed in the update software. Now change comm1 parity to E and try an upload. No go change parity to N and try an upload. I never heard of using Odd parity but you could try it. If these fail then do the combinations parity but also change data bits 7 or 8 and if still no go, try all combinations with stop bits 1 or 2. There is 1.5 but again I never used this in my updates.

I know this will take time but will elimate the settings from the issue. Each time you try a new combination try an upload.

Good luck

Also forget about v1.6 and do v1.5 as that is what I have. Also read carefully the readme dic ha came with the update software for hints on where the rom files should reside on your pc and what the filnames need to be