I am getting following error when change "SharePoint Timer Service" in service account in WFE server.
The account name is invalid or does not exist, or the password is invalid for the account name specified
You should not do it via services console. SharePoint Timer Service should run under the farm admin account. If you want to update the password for it then
If you want to change the farm admin account then follow the below stsadm command.
stsadm.exe -o updatefarmcredentials -userlogin DOMAIN\username -password password
Or try to login with the farm admin account then try to change the Sharepoint timer service under your farm admin account. as it is only running under local account on one server out of 3.