HELP

Hello, thanks for choosing Dell. These are the things you can try:
1 . Cold power drain 

2. We need to check the status though IDRAC

3. Last resort: Minimum to post
Minimum to POST for the R740:
One processor (CPU) in socket processor 1One memory module (DIMM) in socket A1One power supply unitRight control panel and cable (for power button functionality)System board

You can first try to configure the system minimum to POST and see whether the server is powering ON.

Minimum to POST configuration is the configuration that has the minimum components required to complete POST. Typically, the minimum to POST configuration is PSU1, CPU1, memory module in A1 slot, and the default riser without expansion cards.