Air carrier Captain reported electrical system failures that caused several systems to fail and a strong electrical odor in the cockpit while on the ramp prior to departure.

Narrative

We boarded the aircraft and noticed the screens were on in the flight deck and the cabin lights were dim. The FO stepped off to perform the walk around. I began to perform first flight of the day items. Circuit breakers were checked and none were popped. I turned the battery master on; performed a fire detection test; and started the APU. Once the APU was running a Display Cool Caution MSG came on and a red Display Temp Warning came on. Then the BATT MAIN circuit breaker popped along with the Cabin Lighting circuit breaker. I decided to shutdown the aircraft entirely as an electrical odor became stronger in the flight deck. The FO stepped into the flight deck and noticed the smell immediately. Dispatch and MX (Maintenance) were called. After several hours the flight continued with 3 MELs. The FO's PFD (Primary Flight Display) screen failed along with the GND (Ground) display fan. Cause: Unknown but contract MX and company MX suspect faulty ground power lead to the failure. Suggestions: To prevent screen failures add dim all screens to the secure checklist and ask MX personnel to dim screens after being onboard if applicable.