Thanks jraef. [thumbsup2] Same as we suspect that a stray voltage and current is passing through that board. This elevator has been running for more than 10 years without major failure and we have not modified any wiring. Could there be 24Vdc short circuits, from push buttons etc, because before...
The main controller board BP 304 has its IC chip burned in the relay board. Its history was that, there was an intermittent stop or it will flash a " tripped" event. Then after several power reset, it will return to normal.
Then one time, it just stopped, then after resetting the power, a burnt...