[Premium-Rx] Looking for HF-2050 schematic part

[rxcontrol at free.fr]

Hi all,

I'm trying to solve an issue with the RS232 remote control link of my HF2050.
I guess that the line driver broke. A quick look to the PCB shows that this
receiver doesn't use the usual line drivers (such as 1488/1489) but instead
transistors.
Does anybody have the schematic for that part ?
It would avoid me having to reverse it.

Many thanks

Bertrand
http://rxcontrol.free.fr