black screen error

[pcnextvpr]

hi,
my intel motherboard ( dg31pr ) was not working.
* I try to check cmos battery and change the new one but the same problem.
* And Flashing My Bios to new Version ( But No use )
* And try to CMOS jumper to Config mode the system will be on and shows " cmos checksome error and change the date and time" i try to change ( but no use )
* And i hear 4 beeb sound
* and i try to change my crystal ic to new one ( but no use )

WHAT CAN I DO ( *** Sorry for my Bad English *** )

 

[cin19]

And i hear 4 beeb sound

Double check your MB beep code, and the code from intel legacy MB https://www.intel.com/content/www/us/en/support/articles/000005473/boards-and-kits.html

if you are sure the beep code is the 4 beeps, and because you try change the timer, I don't know you try use the new CMOS battery or not, if you did replace the battery, the MB may have problem.