Hi, I have a very strange problem with my HP ProBook 4540s so ANY help is appreciated: Press the Power button, the power LED turns on for like 1.5 seconds (including the caps lock, AC LED and also fan, the display doesn't turn on) and then turn off and then he tries to startup again and sometimes it does show the HP screen and boots normally sometimes doesn't and turns off and then on for 1.5 seconds and so on and on... I tried: - Reflash the latest version version of BIOS - Rollback of BIOS doesn't work (invalid signature file says when I try to flash the BIOS but I tried different versions but same problem) and I still have no solution for this to work. - Take out SSD. - Take out the RAM, I tried switching the slots but has no effects. - I tried reset the BIOS via taking out the CMOS battery. I even replaced the battery and nothing. The problem is present no matter if I am on battery or AC power. It happens randomly, sometimes it boots up on second try sometimes on first try sometimes at all. I hope that I explained the problem good enough, If you have questions please ask me because this problem is driving me nuts !!!
Problems like this can be a needle in haystack sometimes. One thing first, you successfully flashed with latest bios from HP? If yes we could probably rule that out of the Equation
Yes, but in HP UEFI Diagnostic Tools I have an option called rollback BIOS that's what I used but like I said doesn't work. Why HP put an option that doesn't work is beyond me
Just an example I´m on a ASUS ROG and I have to run ASUS own WinFlash.exe scripted: <start "" "C:\Program Files (x86)\ASUS\WinFlash\WinFlash.exe" /nodate> to rollback BIOS flashing. Does HP have a similar way to do it? If you strip everything out of your pc - RAM, SSD etc, do you get any POST messages at all?
On HP you have a couple of ways to flash the BIOS: Via HP Utility which installs the BIOS required files to the EFI partition of the HDD and then the BIOS detects those files on restart and flash them. Or you enter into the BIOS the select the file manually. Or via HP UEFI Diagnostic Tools where you have 2 options update or rollback the bios. Both options work if you try to flash the current version of BIOS or a larger one but a previous version doesn't work at all. There is no Windows bios update utility unfortunately. I tried all of them and like I said works only for the current version of BIOS
I get a blinking LED of the caps lock button if I take out the RAM and everything else except the CPU
Keep in mind if you upgraded the memory to +/- 8GB max for you´re Laptop in dual channel the two so-dimms must be of 4GB each and same speed etc .. in single channel I guess 4GB is max by the bios.
I have 8 GB in total. I got this problem with random startup from like 2 months ago. I have 8 GB of RAM from like 2015. So the RAM isn't the problem here. I did test it and seems fine