The client logs are located in the %WINDIR%\System32\CCM\Logs folder or %WINDIR%\SysWOW64\CCM\Logs (for x64 OS).
The SCCM server log files are located in the <INSTALL_PATH>\Logs or SMS_CCM\Logs folder. IIS logs can be found in %WINDIR%\System32\logfiles\W3SVC1 folder.