Hi @muhammadab87909
Is the amber light blinking or on steady?
Here's a [https://www.dell.com/support/kbdoc/en-au/000126021/a-reference-guide-to-the-dell-optiplex-diagnostic-indicators#2012_to_2020|link] that shows what the problem may be depending on what the amber light is doing.
Find the section on the page entitled ''Diagnostic LEDs for the OptiPlex series (2012 to 2020)'' and click on the ''Power button LED'' link and the ''Diagnostic Indicator table'' link in that section