[K2] Issue with microcontroller on KSB2 SSB adapter
I have an issue with the micontroller (U1, 16C72) on the SSB adapter, it is not switching between CW and SSB filters anymore.
I checked the whole KSB2 board and every component and at the end only the uC was left. Checked then the output levels when switching between CW and SSB (21/RXS, 22/RXC), didn't switch to SSB mode, only CW, independent of the setting.
Removed the uC from its socket, plugged it into an additional socket where I removed the two pins (21, 22) and pluged this construct into the socket on the PCB. Then I hardwired the pins on the PCB for SSB mode and everything worked perfectly.
I have no idea how the uC can get damaged during operation ...
I assume the uC is controlled via the AUXBUS and for whatever reason it is not switching these two pins anymore. The rest is working perfectly.
Any idea what happended or how this can be solve? Re-programming of the uC, in case the hex file is available somewhere? Otherwise I probably need to order a new uC?