Here is a solution from the Pioneer web site:
Important: Updated Information Regarding Free Power Supply Replacement for Certain Pioneer Plasmas
Pioneer is continuing to offer a free, in-home/office power supply replacement for certain of its second and third generation plasma models listed below for customers who experience a problem with the original power supply. If a model is not listed below, no power supply replacement is needed and no further action needs to be taken.
If you own or use a plasma listed below, please call our toll free hotline at 1-800-421-1404 to arrange a time to have your plasma's power supply upgraded at your residence or office at no charge.
Plasma Models (15 listed):
The issue with the power supply in the plasmas listed above does not pose any health or safety risk. Pioneer has received reports that the power supply in the affected models may fail. In some cases, a loud popping sound can be heard when a power supply fails. After the power supply fails, the plasma is no longer operable.
Anyone with questions can call Pioneer's toll free hotline at 800-421-1404.
We apologize for any inconvenience.