Older laptop with Lubuntu 18 hibernates during bootup

[ramanterola]

I recently installed Lubutu 18.04 LTS on a Dell inspiron 700m ( Pentium M 1.70 Ghz, 1.26 GB RAM). When I first boot up the computer, I see the harddrive light and feel the harddrive, wifi comes on, the screen flickers, in summary the computer is booting up. The suddenly the computer goes to sleep.
I can press the poser button and the boot up sequence continues, it usually requires three presses of the power button (It goes to sleep or hibernates 3 times ) The last on in the middle of the login screen. Once the login is completed, the computer works perfectly for as long as I want.
I am somewhat of a noob, so I need help. How can I trace what takes my computer into hibernation?
Thank you in advance for your help.
R

[mörgæs]

Hi, welcome to the fora.
I have seen similar problems when the power supply is not strong enough. Is it the original one?

[Autodave]

Going along with morgaes: how many devices do you have connected while booting? Try disconnecting all unnecessary ones and try booting.

[ramanterola]

Thank you mörgæs & Dave for the quick reply.
The charger is an original Dell brandname charger. Since I have a couple, I have tried several chargers with the same result. The battery is also good (providing hours of usage), so I tried to boot up just with the battery: Same result.
There are no external devices connected, the computer is exactly as it came from Dell.
Any other ideas?
Thx
R

[egeezer]

Next time you get it into the properly-running state, check all possible configuration options in the Power Manager section. There might be something there that will give you some clues. (Not a Lubuntu expert, just thinking what I would do in your case!)

[oldfred]

Are you sure it is going to sleep, or just slow booting?
My systems have SSD and boot very quick, but I get a bit of a black screen. On a slow system it may seem like it has stopped?