while i know your problem has been resolved, for the others interested in this issue you can program many of the uniden scanners with the rear db-9 using a null-modem adapter or cable and either a serial port on your computer or a usb-serial adapter.
While i know it works with the bct15, bct15x, bcd996t, xt and p2, i haven't tried this on a bcd536hp though it should work for serial mode.
The front serial port and usb ports are easily damaged. I have broken a couple of them over the years and used the rear db-9 instead when needed.
For my 996xt's in the truck i installed a 3.5mm stereo jack on the rear panel to use with the rh-96. I have not tried programming with this jack however. (the rh-96 will also work on the rear serial port with a properly constructed cable on any of these except the 536 and p2.)
is a serial cable that would work with a serial port or a serial to usb adapter.
looks interesting. It is a usb-serial adapter with built-in null modem adapter. While i haven't tried it myself, it should do the job directly with no other adapter.