#To verify the Root CA CA.pem and Intermediate CA ICA.pem
openssl verify -CAfile CA.pem ICA.pem

#To create the CA chain ( In Linux or just add files together in notepad for Linux ) 
cat ICA.pem ca.pem > CA-chain.pem

#To verify the CA chain and the web cert
openssl verify -CAfile CA-chain.pem web.pem

#To generate checksum of the private key
openssl rsa -modulus -noout -in private.key 

#To generate checksum of the web cert, the checksum result should match with the private key
openssl x509 -modulus -noout -in web.pem

Exporting files for further diagnosis

openssl rsa -in private.key -text -noout
openssl x509 -in web.pem -text -noout
openssl x509 -in ica.pem -text -noout
openssl x509 -in ca.pem -text -noout