Boot to black screen with blinking white cursor

Hello experts, noob here.

Not sure where to post this troubleshooting question on the forum, so please feel free to re-locate it to it's appropriate place as needed.

PROBLEM: Computer boots to black screen with blinking cursor.
There appears no way to access bios . tried f2,f10,and delete,
Just goes straight to the black screen with cursor. No response from the keyboard, keyboard lights don't even light up.

What Happened ?? : I tried connecting an IDE hardrive to my Dell optiplex . It normally runs on an SATA harddrive. To connect the IDE, i used the cables from my cd/dvd rw drive, maybe that was it, idk.

But when I turned it on I got a black screen with a blinking cursor, with no bios start screen at all.
That freaked me out, so i disconnected the new hard drive and put everything back the way it was.

Still, just a black screen with a cursor.....

so, how do I get to bios.

Tried: disconnecting from power, removing motherboard battery for 30 sec. while holding power button. Disconnecting the hard drive and starting produced the same result.....

Help please. I'm trying to avoid this being the second computer I have fried !!!!

I put it into alternative operating systems because It has Zorin on it........Everything I search for on Bing mentions windows XP and windows 7...Though I doubt that makes a difference.....maybe it does

Great !!! I removed all of the RAM, put the top one in the bottom one, and it booted right into zorin !
Now I Just need to figure out how to get all the ram in right, if that is even possible. Because now I am running on just the one that I know works. Any advice?

Admin: feel free to delete this post,

10 viewersr that did not reply, Now you know that if you see this question again, tell them to remove their ram, and try one at a time.....

you got no post beeps?

No beeps. I'm not really sure what post is though,
I know it stands for Power On Self Test, I always thought it was what the computer did when you plug in the power, and it turns its lights on for a few seconds and then shuts down real quick.But none of my other computers do that, so I was confused about what post is.
But I did notice that it stopped doing that after I messed around with resetting the motherboard battery and such,
let me go check it to see if it still does that are not.
Is that what POST is?..........

well it does it now,

it is power on self test, and then it gives you the chance to enter bios, then boots the os.
the beeps I ask about are the results of the self test, in a normal boot you get one beep, t beeps I think is memory issue, four beeps is gpu issue.
you must not have a motherboard speaker.

The beep seemed normal. Then after reseting the battery,
it didn't seem to go through a post at all.
_All is well after removing the 4-1gb old school ram, and re-inserting 1..of them.


More research for the GX620 database.
I'm gonna drag that thing to the limit.........