Polar 76 SD-P: KK board with V2 and V3 leds on

If the machine is turned on without YSB connected the two leds remain off. Nevertheless, the electric resistance in YSB is in normel range: 36,7 ohms.
Although the b.sbe and b.sba sensors has been tested and the signals go to KK and IAR, the V3 led on IAR card is off.
After turn on the machine, touch the keyboard generate a 06 in display and in few seconds a 86.

 

If HK led 14 ,18 is lit exchange HK
If Iar card led v3 off change Iar

Exchange ar kk
Check bad connection shorts