Why PC cannot ping ASA

Hi It is strange that the PC cannot ping the ASA. The topology is like this ASA(inside)---DeviceA----PC. the ASA can ping PC and DeviceA, but PC cannot ping ASA. When PC ping ASA, we can see message of debug icmp(debug icmp track 255 in the ASA) from the PC. The DeviceA can also ping both ASA and PC. I check the ASA config, which does not any limit to icmp. Capture show the ASA can receive message, but did not send any message to the PC. Anyone can give some suggestion ? Thank you