[SOLVED] Optiplex 780 desktop turns on but after a couple seconds I can't see nothing on the screen but it's still on just no picture ?

[Luxuriousyaya]

I have a Optiplex 780 desktop but when I turn it on after about 5 seconds the screen turns black but the computer is still on i just can't see anything on the screen ? Can someone please help ?

 

[punkncat]

Given the age of that machine, it could be anything.

Ideally you have another monitor, or cable you could test it on.
Beyond that, and without knowing if you have modified it, added a GPU, etc. it would be impossible to make any real recommendation beyond pony up some money for something a decade or so newer?

 

[Luxuriousyaya]

Thank you so much i just cleaned it thinking it was probably the dust and i changed the round battery from the inside but no i didn't solve the problem i turned it back on and i notice it turns on it shows the dell logo and then it stops it beeps two times before stopping and on the bottom the numbers blink and after number 4 there is another light that stays on and then it turns off it looks like a cylinder like a battery well thank you so much for taking time on replying to my problem thank you i really appreciate it

 

[AntonyLovric]

If you change the battery, you'll need to go into the bios and check the settings. (changing the round battery would probably change the settings in BIOS).

Read the following posts:

Dell Optiplex 780 Will Not Boot Up - Dell Community

You might want to go into the BIOS and if you know enough, check the devices, settings, date/time, etc. If you feel confident, you can usually 'load setup defaults' and try to reboot.