Gardena lawnmowerrobot mainboard, short out battery

[Stigsolbjerg]

hi again
this time its a mainboard from a mowerrobot, when i connect battery it shorts it, so the bms shuts down battery.
when take the mm in beepmode and measure from the positive to the negative battery terminal on the board it beeps shortly like 0,25 sec, and when i reverse the probes it beeps again shortly 0,25 sec.
when i mesure on the cap thats missing in pic nr 2, the bottom solderpath goes to the negative, the upper one is 1,2 ohm to negative is this a short?

hope Capleaker is still around

[DriversScrew]

Could be a short. Depends on how accurate your multimeter is.
I would try to inject a low voltage and search for shorted components getting hot on the pcb. A thermal camera would be helpful.

[petehall347]

the beep is capacitors charging up

[Stigsolbjerg]

Hi again had a Quick look today at the print. 10 Big resistor below the 4 pin plug for the batteri, its the one with 10M written on it, is it right that it is 0,01 ohm? Can not find a true match on the internet.

[petehall347]

10 MEG . what does it measure ?

[Stigsolbjerg]

Think it was 0,12 ohm

[petehall347]

must mean 10 milliohm 0.01 Ω.. confusing with the capital M Megohm

[Stigsolbjerg]

It is measuring 10,1 milli ohm.
think i must try this voltage injection thing. I have this rd6006 switch mode psu. Any recomadation for settings?

[petehall347]

have you tested the battery ?

[Stigsolbjerg]

No, just the voltage it is 18 volt. When i connect it, it is 0,8 volt, it gives a little spark when i connect it

[petehall347]

battery is maybe dead then by the looks of it . see if it will power something else .