i have a dell latitude it worked well but from nowhere it shut down and when i re turn it on it gave me a black screen with the caps lock and scroll lock and num lock flashing blue the battery is good and new
I had something similar a few months ago (it ended up being a problem with the power button of the laptop itself).
Before getting that fixed I tried the following (and they re-tried as part of the support process):
How to Use Forced ePSA to Recover from POST or Boot Failure on Dell Latitude PCs | Dell Canada
How to Reset the Real-Time Clock to Recover Your Dell Laptop | Dell Canada
No harm in trying.
i tried this and now the caps is flashing for some time then light without flash