Suppose server x is not able to reach server y through the ASA firewall how you will troubleshoot the connectivity?

To check if the access is allowed through the ASA you can use the command packet-tracer

packet-tracer input Inside tcp 80 (source address/port) 80 (Destination addree/port) detailed

Packet-tracer will check multiple parameter such as nat,cal,route etc to check if the access is allowed or not.

If something is blocking the access it will shown in the details such as below

Phase: 3
Subtype: log
Result: DROP
Config: access-group inside in interface inside access-list inside extended deny tcp any host eq 5282

In this example it is showing that access-list is blocking the access.