Question System has Power but No Post or Display

[TewksDotDash]

I bought a Dell Optiplex 990 the other day. The system has power but doesn’t show a post screen or a display output. The display port detects something is connect but nothing else. There is no beep codes or led error codes as well. Any suggestions?

I have tried
Clearing the CMOS
Reseating the RAM
Swapping the RAM for a different kit
Adding a graphics card
Taking the entire system apart and put back together

 

[Aeacus]

Any suggestions?

Replacing MoBo should fix it.

Or if you want to do more troubleshooting, a checklist to do,
link: https://forums.tomshardware.com/thr...deo-output-troubleshooting-checklist.1285536/