Navibot Cornerclean sr10f71 - Charging Station Leds Fault

[ZAPPAGOBLIN]

Hi!. I'm a new user of this forum and first of all I would like to greet all users. I hope you can help me. My robot no longer charge. I purchased a spare battery (the previous one was completely discharged) and the robot turned on, starting the countdown and signaling low battery. Put it on the charging base and nothing happens. But the LEDs of the charging base light up SIMULTANEOUSLY, then fade and after about a second or two they turn on again. The phenomenon continues to repeat itself, and at the end the robot does not load. I measured the voltage on the charge terminals but I see 0 volts at no load. Can anyone suggest the reason for this? Thanks for your help!