DELL PRECISION 490 1 2 3 solid light

Try changing the cmos battery

on that picture, top-left, just under the power supply connector

hey,

i couldnt find any cmos battery on my motherboard

By what I'm seeing online ( googling ) it's possible that is caused by the videocard failing.

Do you by chance have a spare/older one to test ?

i just replaced it i upload a video please help

See page 28-29 here--Precision 490 Desktop Quick Reference Guide (dell.com)

But a new battery anywhere batteries are sold for ~$1.

I think  that's  actually the problem  since  my smart vacuum actually disconnected  the cable maybe it did something.

I don't have another  graphic card at  the moment but I will search  maybe  I will take from my neighbor.

Is it possible  to boot  without a video xard

ok, thanks you for helping i just found it (was hidden behind cables) and replaced it

but still lights 1 + 2 + 3 keeps on

it also beeps at me twice when i boot system

here is a video

https://drive.google.com/file/d/1IwSo-_cIYCvjpeqLOwBbJCMGRjknaDMI/view?usp=sharing

please help

on a server , yes

otherwise usually no, but it depends on the bios.

Disconnect hard drive and turn on it should show boot error.

The Precision 490 doesn't have onboard graphics.  The same for many Xeon CPU's.

@xbenten  You might want to also try a new video cable.  Not sure how hard of a hit it took, but it's normally not easy to just yank them, especially if the screws/thumb screws were fastened.

Step 1: open the system unplugged the cable from the hard drive wait for sec and then plug back the cables and run the system again.Hopefully this step will work if not then try step 2

Step 2: if you open the system there will be a cell on the motherboard remove it and replace it with the new and your issue will be resolved.

i uploaded a new video showing my boot sequence please help

https://youtu.be/7fm4wmhwgT0

Did you replace the size 2032 CMOS battery? 

Check each RAM chip one at a time to make sure it is good.

A reference guide to the Precision Workstation Diagnostic Indicators 

As for the beeping, unless I'm missing something, didn't seem to be beeping a code.  So I just went with the diagnostic numbers.  Hopefully I saw the small lights ok in your video, that they're 1,3.

If I remember right, the generic beeping may indicate an MB problem.  So start with the battery and RAM as mentioned and we'll go from there.