Bricked Controllino ? Reset LED lit permanently

Hi Guys,
I recently obtained a Controllino Mini to be used in a small industrial project. While checking it out I also wanted to test the built-in RTC capabilities. In doing so I toyed around with the available commands from the supplied library. After uploading another sketch it seems I have bricked the Controllino, since I cannot upload anything else :

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00

and the reset LED is permanently lid. When looking at the pinout diagram of the Controllino Mini I saw that there was a small remark near the top stating

Not proper handling of the RTC/INT output can cause permanent controllino reset

, so I guess I somehow reached that state.
Since I am pretty new to the whole Arduino / Microcontroller scene I don’t really know where to go from here.
Is it a viable idea to try and burn a new bootloader ?
Is there a simpler way to reset the state of the device?
What did I even do wrong ?
Any help is greatly appreciated !
Christian

PS: Since I can’t find source tags i will put my sketch in a Quote below:

#include <Controllino.h>


unsigned char day, weekday, month, year, hour, minute, sec;
#define analogInputPin A0
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(analogInputPin, INPUT);
/*Controllino_RTC_init(1);
Serial.print("Initalized RTC: ");
Controllino_SetTimeDate(1,6,4,2016,15,14,10);*/
}

void loop() {
 // Controllino_ReadTimeDate(&day,&weekday,&month,&year,&hour,&minute,&sec);
  float voltage = 15*(analogRead(analogInputPin)/1023.0);
  Serial.print(hour);
  Serial.print(":");
  Serial.print(minute);
  Serial.print(":");
  Serial.print(sec);
  Serial.print(" : ");
  
  Serial.println(voltage);
 

}

Seems like a problem specific to controllino - you might do better on their forum? Arduino boards don't even have a reset led, because none of the arduino boards have that failure mode. They have all sorts of other ones, of course, but not that one. They don't tell you much about the design of the board :-/

For the sake of 'completeness' of this answer, I am pasting the reply from the originl poster from a parallel thread on: atmega328 - Did I Brick my Controllino? - Arduino Stack Exchange

I just received an answer from the official team which should work, I'll leave it here for further reference:

Open the device and disconnect (remove) connection board for approx. 30 seconds from the control board – RTC is disconnected from power (gold cap disconnected) and because of that there is reset of all RTC registers.
Plug the connection board back in to the control board. Now we need to rewrite the SW inside the Controllino which caused wrong RTC setting.
Open the Controllino example RTC sketch in Arduino IDE and prepare it to upload (function Controllino_RTC_init(0); shall reset all registers inside the RTC).
Pres and hold reset button on the Controllino device.
Connect the USB Cable (still hold the reset button, SW inside the Controllino doesn’t start)
Click for upload the sketch in Aruduino IDE and wait for „uploading“ message on debug line, than immediately release the reset button and uploading shall be finished (=> hold the reset button during the compiling phase)
If not successful, repeat the procedure