hi,
Well you have said that back panel indicator stays Yellow (Amber it should be).
I assume you are mentioning the PSU indicator (Power Supply Unit).
If the PSU indicator turned on it means that PSU has shut down due to an Internal Protection event and needs Service Attention.
If you have configured ALOM it will be much easier to detect the error. They will be logged in syslog. It will generate an Automatic mail as well.
Its better to run Sun Management Center and Hardware Diagnostic Suite to detect, avoid and manage such situation.
However if the Front Bezel Indicator is on (Service Indicator - Yellow) means that a Problem is Detected and needs the Attention of a Service Personnel.
Its not possible to detect an error remotely but it should be a misconfiguration (during usage) or a hardware failure.
Have you been using it or is it the firs time?
If so you haven't powered the system on in the proper manner.
Its better if you can read these two important publications.
Link 1
Link 2
You will be able to see and identify what when wrong or what you have done wrong.
You can use built in tools as well to detect errors during post.
Administration Guide is located
here.
Please rate the answer if it helps you to overcome the issue.
Feel free to contact again.
Thanks for using Fixya!