[mattydr67]

If I do not make a mistake that tool is made in Russia
That tool it has a diffrent desine then a china clone ( that its 1:1 with opcom rev b genuibe obe but with a diffeen pcb designe )
So in this case this tool is useing a diffren firmware, a small moded one for that schematic. I only supoose.
Never had this kind of tool in my hand
Similar is happend with the chinese opcom v6 hardware
If you are useing it with opcom china clone 2010 all its ok but if you change the software and you are useing it with vauxcom 120309a the tool is not working on k-line.
Just because the hardware its moded and the firmware its moded for this gardware too
If this is your problem then to fix this issue you need a untouched tool, same as the one you have. Extract the Pic MCU dump and reflash with your tool
So if you reflashed back you tool with the same firmware as this time and its not working on k-line then you have to check the relay for pin 7 and then the 9637D ( if it is used this chip )
Keep us informed
Goid luck