Dell optiplex 390 constant beeping on start up. After a while windows starts normally

[skipper00123]

Hi. I have a Dell optiplex 390 MT I3 processor that makes a constant beeping sound right after i see the Dell logo and keeps going nonstop until i see windows loading screen after that i can log in to windows normally ( i should mention that with the beeping problem booting time has been increased a bit) .. I should mention the following issues i had too:
The computer used to restart by itself. I solved this problem just some days ago by replacing the power supply unit.. I also should mention that the PCIe slot isn't working.. And sometimes when the computer start the mouse isn't working and no cursor is visible too until i unplug and plug the mouse to another or the same usb port. Those problems used to happened and still happened with the present beeping problem. I run diagnostic it comes always clean no memory issue cpu test pass. Fans are ok. Hdd passes the test too. I suspect a dying Motherboard. Please any help will be appreciated.

 

[Tyler Paul_1]

I say ditch the old stuff and upgrade asap it seems to me that the motherboard is on its way out especially with that dead pcie slot.

 

[skipper00123]

Well upgrading isn't an option for me right now. If i can't fix this computer i ll have to live without one for a while.. Are motherboard issues fixable? I mean by a technician or someone who fixes computers and is it cheaply replaceable? I can keep the cpu and ram and buy a new motherboard?

 

[Tyler Paul_1]

since everything on a motherboard is soldered its unlikely people can fix it I mean a new motherboard could be an option but we don't know its that for sure.

 

[skipper00123]

What can I do to figure out if it's the motherboard.. ( I forgot to mention that the beeping problem started when I turned on the pc after windows 10 installed updates during previous shutdown.) I reset system and formatted hard drive I also downgraded bios driver to A09 version. Cuz i updated it some days ago...)