SB2209 Electrical Burning Smell

After moving from tap mechanical switch to Voron OptoTap PCB v2.4.1 5-24V, an electrical burning smell was evident.
opto tap indication red/blue was ok. i didn't select 5 or 24v pad at the back of the pcb !
After returning to mechanical switch no more smell (already burnt!), no evidence of heat damage onto opto tap or EBB, the only symptom rgb leds remains off! nil time so far to carry out a trouble shoot, might be front face was not in line with the connector ?

Review the OptoTap PCB v2.4.1 5-24V wiring, the unselected 5/24V pad, and the connector alignment described in the report. Inspect the OptoTap and EBB for the cause of the burning smell and determine why the RGB LEDs remain off; document the findings and any required corrective action.

Written by the indexing model from the issue text.